Architecture découplée grâce aux Reactive Extensions

Auparavant, les applications se connectaient à une seule base de données. Aujourd’hui, elles doivent communiquer avec un ensemble de base de données et composer avec des services web distants. Elles ne sont plus des blocs monolithiques, mais distribuées sur différents serveurs sur différentes zones géographiques. Elles sont “scalables” mais elles doivent maintenant attendre les réponses d’autres applications.

Comment profiter de ces temps d’attente ? Comment casser ce couplage temporel ? Comment transformer un couplage applicatif fort en couplage lâche ?

Cette université fera le tour de RxJava et RxJs. Comment les mettre en place sur un projet et dans une équipe. Et surtout comment utiliser ces bibliothèques pour découpler votre architecture.

University - 20 Avril 2016 - Devoxx France (Palais des congrès de Paris)

David Wursteisen - Brice Dutheil

Note cette présentation est la même que https://speakerdeck.com/dwursteisen/architecture-decouplee-grace-aux-reactive-extensions

Vidéo : https://youtu.be/4To7s3qln2s

Transcript

1. #DevoxxFR #Rx
   Architecture Découplée
   grâce aux Reactive Extensions
   @BriceDutheil @dwursteisen
   Mercredi 20 Avril - Amphi bleu - 9h30
   

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2. @BriceDutheil @dwursteisen
   #DevoxxFR #Rx
   Ce que nous allons voir
   

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3. @BriceDutheil @dwursteisen
   #DevoxxFR #Rx
   Ce que nous allons voir
   Reactive Extensions
   en théorie
   

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4. @BriceDutheil @dwursteisen
   #DevoxxFR #Rx
   Ce que nous allons voir
   Reactive Extensions
   en théorie
   en pratique
   

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5. @BriceDutheil @dwursteisen
   #DevoxxFR #Rx
   Ce que nous allons voir
   Reactive Extensions
   en théorie
   en pratique
   sur notre application
   

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6. @BriceDutheil @dwursteisen
   #DevoxxFR #Rx
   Ce que nous allons voir
   Reactive Extensions
   en théorie
   en pratique
   sur notre application
   Pause
   

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7. @BriceDutheil @dwursteisen
   #DevoxxFR #Rx
   Ce que nous
   ne verrons pas
   

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8. @BriceDutheil @dwursteisen
   #DevoxxFR #Rx
   Ce que nous ne verrons pas
   Énumération des opérateurs
   

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9. @BriceDutheil @dwursteisen
   #DevoxxFR #Rx
   Ce que nous ne verrons pas
   Énumération des opérateurs
   Mieux que ces alternatives ?
   

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10. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Ce que nous ne verrons pas
    Énumération des opérateurs
    Mieux que ces alternatives ?
    Expliquer tous les patterns
    d’utilisation possible
    

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11. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Qui sommes nous ?
    

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12. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Indép’
    Ingénierie
    logicielle
    

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13. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Formation
    Conseil
    Consultant
    

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14. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    https://youtu.be/TT8TLS2Ac0o
    

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15. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    #DevoxxFR #Rx
    

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16. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Êtes-vous familier avec
    RxJava ?
    

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17. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Êtes-vous familier avec RxJava ?
    Oui Non
    

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18. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Êtes-vous familier avec RxJava ?
    Oui
    

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19. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Êtes-vous familier avec RxJava ?
    Non
    

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20. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Architecture Découplée
    grâce aux Reactive Extensions
    

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21. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Le couplage temporel
    

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22. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Application typique
    war
    tomcat
    

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23. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Connaissez vous le
    fonctionnement de
    Tomcat ?
    

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24. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Connaissez vous Tomcat ?
    Oui Non
    

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25. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Connaissez vous Tomcat ?
    Oui
    

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26. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Connaissez vous Tomcat ?
    Non
    

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27. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Examinons le
    cheminement
    d’une requête HTTP
    

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28. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    client
    nouvelle
    requête
    

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29. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    client OS
    Négociation TCP
    nouvelle
    requête
    

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30. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Tomcat / BIO
    client OS
    Négociation TCP
    Requête #
    nouvelle
    requête
    connexion établie
    prête à être
    consommée
    

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31. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Tomcat / BIO
    client OS
    Négociation TCP
    Requête #
    nouvelle
    requête
    Acceptor
    Thread
    Accepte la
    requête
    connexion établie
    prête à être
    consommée
    acceptedCount =
    

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32. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Tomcat / BIO
    client OS
    Négociation TCP
    Requête #
    nouvelle
    requête
    Acceptor
    Thread
    connexion établie
    prête à être
    consommée
    Accepte la
    requête
    Requête donnée aux
    threads de travail si
    slot disponible
    Worker
    Executor
    maxThreads =
    

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33. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Tomcat / BIO
    client OS
    Négociation TCP
    Requête #
    nouvelle
    requête
    Acceptor
    Thread
    connexion établie
    prête à être
    consommée
    Accepte la
    requête
    Requête donnée aux
    threads de travail si
    slot disponible
    Thread
    

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34. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Tomcat / BIO
    client OS
    Négociation TCP
    Requête #
    nouvelle
    requête
    Acceptor
    Thread
    connexion établie
    prête à être
    consommée
    Accepte la
    requête
    Requête donnée aux
    threads de travail si
    slot disponible
    Thread
    w
    a
    r
    Lit la
    payload
    war
    

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35. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Tomcat / BIO
    client OS
    Négociation TCP
    Requête #
    nouvelle
    requête
    Acceptor
    Thread
    connexion établie
    prête à être
    consommée
    Accepte la
    requête
    Requête donnée aux
    threads de travail si
    slot disponible
    Thread
    w
    a
    r
    Lit la
    payload
    Business
    war
    

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36. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Tomcat / BIO
    client OS
    Négociation TCP
    Requête #
    nouvelle
    requête
    Acceptor
    Thread
    connexion établie
    prête à être
    consommée
    Accepte la
    requête
    Requête donnée aux
    threads de travail si
    slot disponible
    Thread
    w
    a
    r
    Lit la
    payload
    Écrit la réponse,
    ferme la
    connexion
    Business
    war
    

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37. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Tomcat / BIO
    client OS
    Négociation TCP
    Requête #
    nouvelle
    requête
    Acceptor
    Thread
    connexion établie
    prête à être
    consommée
    Accepte la
    requête
    Requête donnée aux
    threads de travail si
    slot disponible
    Thread
    war
    Lit la
    payload
    Écrit la réponse,
    ferme la
    connexion
    Business
    

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38. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Premier constat
    Files d’attente
    OS
    

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39. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Un thread
    par requête
    

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40. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Plus de
    thread
    Plus gros
    hardware
    

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41. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Plus de
    thread
    Plus
    de serveurs
    

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42. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Application typique
    war
    tomcat
    service tiers
    

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43. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Avec une
    base de données
    

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44. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Tomcat
    client OS
    Négociation TCP
    Requête #
    nouvelle
    requête
    Acceptor
    Thread
    connexion établie
    prête à être
    consommée
    Accepte la
    requête
    Requête donnée aux
    threads de travail si
    slot disponible
    Thread
    w
    a
    r
    Lit la
    payload
    Écrit la réponse,
    ferme la
    connexion
    Business
    war
    

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45. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Client
    Nouvelle
    requête
    Thread
    war
    Temps
    

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46. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Client
    Nouvelle
    requête
    Thread
    war
    Plus de requêtes en base
    Plus long à répondre
    

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47. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Client
    Nouvelle
    requête
    Thread
    webservice.api
    microservice #
    war
    Avec d’autres dépendances
    

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48. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Tomcat
    client OS
    Requête #
    nouvelle
    requête
    Acceptor
    Thread
    Attend un slot
    disponible
    Thread
    war
    Executor
    full
    

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49. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Point de vue du CPU
    Pas d’instruction à exécuter
    Le système attend sur des I/Os
    

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50. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Deuxième observation :
    Couplage temporel
    

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51. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    On attend
    Services distants
    Base de données
    Fournisseurs tiers
    

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52. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Localement aussi
    Lecture/Écriture sur disque
    - ex : swap
    Panne hardware
    - ex : disque en panne augmente la latence
    

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53. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Solutions ?
    

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54. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Augmenter le
    nombre de
    thread Tomcat
    

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55. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Utiliser d’autres Executor
    

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56. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    C’est toujours bloquant
    et ça peut devenir
    complexe
    

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57. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Revient à
    augmenter
    le nombre
    de thread
    

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58. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Sur Tomcat, utiliser un
    autre connecteur ?
    NIO, APR, NIO2 (Tomcat 8)
    

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59. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    NIO ne résout pas le
    problème de fond
    §9.2 The Container Provider should ensure that the
    dispatch of the request to a target servlet occurs in
    the same thread of the same JVM as the original
    request.
    http://download.oracle.com/otn-pub/jcp/servlet-3.0-mrel-full-oth-JSpec/servlet-3_0-mrel-spec.pdf
    

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60. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Tomcat / NIO
    client OS
    Requête #
    nouvelle
    requête
    Acceptor
    Thread
    Thread
    Poller
    Thread
    Requête #
    war
    

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61. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Tomcat / NIO
    client OS
    Requête #
    nouvelle
    requête
    Acceptor
    Thread
    Thread
    Poller
    Thread
    Requête #
    war
    

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62. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Ne pas oublier
    le tuning
    

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63. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Ne pas oublier
    le tuning
    mais…
    

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64. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Comprendre la JVM
    

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65. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Long à établir
    

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66. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Change avec
    la charge / le business
    

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67. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Dans tous
    les cas
    Tomcat
    

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68. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Dans tous
    les cas
    Notre application
    

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69. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    

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70. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Améliorer le code de
    notre application
    

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71. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Améliorer le code de notre application
    • Executors
    • Future
    

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72. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Améliorer le code de notre application
    • Executors
    • Future
    • Embarquer une techno à la ActiveMQ ?
    

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73. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Améliorer le code de notre application
    • Executors
    • Future
    • Embarquer une techno à la ActiveMQ ?
    • Problème de lourdeur, overhead
    

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74. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Améliorer le code de notre application
    • Executors
    • Future
    • Embarquer une techno à la ActiveMQ ?
    • Problème de lourdeur, overhead
    • Quid de la composition
    

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75. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Améliorer le code de notre application
    • Executors
    • Future
    • Embarquer une techno à la ActiveMQ ?
    • Problème de lourdeur, overhead
    • Quid de la composition
    • CompletableFuture
    => Avec Collections ou Streams ?
    

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76. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Améliorer le code de notre application
    • Executors
    • Future
    • Embarquer une techno à la ActiveMQ ?
    • Problème de lourdeur, overhead
    • Quid de la composition
    • CompletableFuture
    => Avec Collections ou Streams ?
    

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77. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Améliorer le code de notre application
    • Executors
    • Future
    • Embarquer une techno à la ActiveMQ ?
    • Problème de lourdeur, overhead
    • Quid de la composition
    • CompletableFuture
    => Avec Collections ou Streams ?
    • Gestion d’erreurs
    

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78. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Le code pour mitiger
    ces problèmes est
    complexe
    

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79. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Le code pour mitiger
    ces problèmes est plus
    obscur au raisonnement
    

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80. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Avez vous déjà rencontré ces problèmes ?
    Oui Non
    

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81. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Avez vous déjà rencontré ces problèmes ?
    Non
    

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82. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Avez vous déjà rencontré ces problèmes ?
    Oui
    

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83. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Quelles solutions ?
    Tuning
    Tomcat
    Pool JDBC
    …
    Changement
    du code
    

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84. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Quelles solutions ?
    Tuning
    Tomcat
    Pool JDBC
    …
    

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85. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Quelle solutions ?
    Changement
    du code
    

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86. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Reactive Extensions
    pour mieux utiliser les
    ressources hardware
    

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87. #DevoxxFR #Rx
    Reactive Extensions
    En théorie
    

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88. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Historique
    

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89. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Historique
    

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90. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Historique
    .NET
    Java
    JavaScript
    

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91. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Historique
    .NET
    Java
    JavaScript
    Scala
    Clojure
    Swift
    

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92. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Historique
    

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93. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Pourquoi faire ?
    Une API pour la
    programmation
    asynchrone
    

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94. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Appel Synchrone - Asynchrone
    Appel synchrone
    versus
    Appel asynchrone
    

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95. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Appel Synchrone
    Client
    Serveur
    

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96. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Appel Synchrone
    Client
    Serveur
    Appel bloquant
    

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97. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Appel Asynchrone
    Client
    Serveur
    

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98. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Appel Asynchrone
    Exécution d’autres
    traitements
    Client
    Serveur
    

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99. @BriceDutheil @dwursteisen
    #DevoxxFR #Rx
    Temporalité
    http://blog.codinghorror.com/the-infinite-space-between-words/
    Temps machine Temps humain
    1 cycle CPU 0.3 nanosecondes 1 seconde
    Accès disque (SSD) 50-150 microsecondes 2-6 jours
    Accès disque
    (mécanique)
    1-10 millisecondes 1-12 mois
    Envoi d’un paquet de
    San Francisco à New
    York
    40 milliseconds 4 ans
    

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100. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Temporalité
     http://blog.codinghorror.com/the-infinite-space-between-words/
     Temps machine Temps humain
     1 cycle CPU 0.3 nanosecondes 1 seconde
     Accès disque (SSD) 50-150 microsecondes 2-6 jours
     Accès disque
     (mécanique)
     1-10 millisecondes 1-12 mois
     Envoi d’un paquet de
     San Francisco à New
     York
     40 milliseconds 4 ans
     

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101. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Pour quoi faire ?
     

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102. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Pour quoi faire ?
     Future ?
     Callback ?
     

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103. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Pour quoi faire ?
     Future future = …
     future.get(); // bloquant !
     

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104. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Pour quoi faire ?
     future1.get();
     future2.get();
     future3.get();
     future4.get();
     future5.get();
     Ordonnancement optimal ?
     

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105. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Pour quoi faire ?
     Future ?
     Callback ?
     

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106. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Pour quoi faire ?
     client.execute(new Callback() {
     @Override
     public void completed(HttpResponse response) {
     }
     });
     

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107. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Pour quoi faire ?
     client.execute(new Callback() {
     @Override
     public void completed(HttpResponse response) {
     client.execute(new Callback() {
     @Override
     public void completed(HttpResponse response) {
     }
     });
     }
     });
     

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108. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Pour quoi faire ?
     client.execute(new Callback() {
     @Override
     public void completed(HttpResponse response) {
     client.execute(new Callback() {
     @Override
     public void completed(HttpResponse response) {
     client.execute(new Callback() {
     @Override
     public void completed(HttpResponse response) {
     }
     });
     }
     });
     

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109. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Pour quoi faire ?
     client.execute(new Callback() {
     @Override
     public void completed(HttpResponse response) {
     client.execute(new Callback() {
     @Override
     public void completed(HttpResponse response) {
     client.execute(new Callback() {
     @Override
     public void completed(HttpResponse response) {
     }
     });
     }
     });
     Callback hell
     

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110. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Pour quoi faire ?
     Future ?
     Callback ?
     

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111. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Comprendre les concepts
     Les technologies passent.
     Les concepts restent.
     

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112. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Concepts applicables
     pour d’autres
     bibliothèques de
     type Reactive Streams
     

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113. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Back to basics
     

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114. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxJava permet de manipuler des
     évènements d’une manière
     synchrone et/ou asynchrone
     

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115. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Flux d’évènements fini
     Diagramme Marble
     

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116. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Flux d’évènements fini
     Évènements Fin du flux
     

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117. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Flux d’évènements avec une erreur
     Évènements Erreur
     

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118. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Flux d’évènements infini
     Évènements
     

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119. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Flux fini sans évènement
     Fin du flux
     

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120. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Quelle est la nature de
     ces évènements ?
     

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121. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     json json json
     Observable
     

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122. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     λ ϕ φ
     json json json
     Observable
     Observable
     

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123. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     λ ϕ φ
     json json json
     Observable
     Observable
     Observable
     

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124. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Comment écouter ces
     évènements ?
     

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125. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observer
     

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126. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     OnNext* (OnCompleted|OnError)?
     

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127. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     OnNext* (OnCompleted|OnError)?
     

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128. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     OnNext* (OnCompleted|OnError)?
     

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129. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     OnNext* (OnCompleted|OnError)?
     

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130. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .subscribe(new Observer() {
     @Override
     public void onNext(Integer v) {
     System.out.println("Valeur : " + v);
     }
     @Override
     public void onCompleted() {
     System.out.println("Fin");
     }
     @Override
     public void onError(Throwable e) {
     System.out.println("Erreur");
     }
     });
     

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131. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .subscribe(new Observer() {
     @Override
     public void onNext(Integer v) {
     System.out.println("Valeur : " + v);
     }
     @Override
     public void onCompleted() {
     System.out.println("Fin");
     }
     @Override
     public void onError(Throwable e) {
     System.out.println("Erreur");
     }
     });
     

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132. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .subscribe(new Observer() {
     @Override
     public void onNext(Integer v) {
     System.out.println("Valeur : " + v);
     }
     @Override
     public void onCompleted() {
     System.out.println("Fin");
     }
     @Override
     public void onError(Throwable e) {
     System.out.println("Erreur");
     }
     });
     

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133. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .subscribe(new Observer() {
     @Override
     public void onNext(Integer v) {
     System.out.println("Valeur : " + v);
     }
     @Override
     public void onCompleted() {
     System.out.println("Fin");
     }
     @Override
     public void onError(Throwable e) {
     System.out.println("Erreur");
     }
     });
     

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134. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .subscribe(v-> System.out.println("Valeur : " + v),
     e -> System.out.println("Erreur"),
     () -> System.out.println("Fin")
     );
     

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135. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .subscribe(v-> System.out.println("Valeur : " + v),
     e -> System.out.println("Erreur"),
     () -> System.out.println("Fin")
     );
     onNext
     onError
     onCompleted
     

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136. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Comment manipuler ces
     évènements ?
     

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137. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable
     

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138. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Transformation à base
     d’opérateurs.
     

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139. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .map(i -> i * 2)
     .take(2)
     .defaultIfEmpty(0)
     .subscribe();
     

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140. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .map(i -> i * 2)
     .take(2)
     .defaultIfEmpty(0)
     .subscribe();
     Opérateur map
     

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141. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .map(i -> i * 2)
     .take(2)
     .defaultIfEmpty(0)
     .subscribe();
     Opérateur take
     

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142. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .map(i -> i * 2)
     .take(2)
     .defaultIfEmpty(0)
     .subscribe();
     Opérateur
     defaultIfEmpty
     

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143. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Liste des opérateurs
     disponibles sur
     reactivex.io
     

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144. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Question :
     Comment convertir une liste de
     mots en minuscules et filtrer
     pour garder uniquement les
     mots de plus de 3 lettres ?
     

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145. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just("bjr", "DevoXx")
     .map(str -> str.toLowerCase())
     .filter(str -> str.length() > 3)
     .subscribe(System.out::println);
     

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146. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just("bjr", "DevoXx")
     .map(str -> str.toLowerCase())
     .filter(str -> str.length() > 3)
     .subscribe(System.out::println);
     Conversion
     

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147. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just("bjr", "DevoXx")
     .map(str -> str.toLowerCase())
     .filter(str -> str.length() > 3)
     .subscribe(System.out::println);
     Filtre
     

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148. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just("bjr", "DevoXx")
     .map(str -> str.toLowerCase())
     .filter(str -> str.length() > 3)
     .subscribe(System.out::println);
     Observable 1
     

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149. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just("bjr", "DevoXx")
     .map(str -> str.toLowerCase())
     .filter(str -> str.length() > 3)
     .subscribe(System.out::println);
     Observable 2
     

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150. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just("bjr", "DevoXx")
     .map(str -> str.toLowerCase())
     .filter(str -> str.length() > 3)
     .subscribe(System.out::println);
     Observable 3
     

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151. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Comprendre les concepts
     Manipuler une
     monade
     

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152. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Comprendre les concepts
     

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153. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Concept de Monade
     Une structure ayant
     - Un type paramétré (Observable)
     - Une factory (Observable.just(...))
     - Une méthode flatMap (obs.flatMap(...))
     - Structure programmatique
     (Grossièrement)
     

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154. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Concept de Monade
     Stream Java 8
     

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155. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Structure programmatique
     List words = Stream.of("bonJour", "bonjour", "Hello")
     .map(str -> str.toLowerCase())
     .distinct()
     .collect(Collectors.toList());
     Factory
     

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156. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Structure programmatique
     List words = Stream.of("bonJour", "bonjour", "Hello")
     .map(str -> str.toLowerCase())
     .distinct()
     .collect(Collectors.toList());
     Étape 1
     

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157. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Structure programmatique
     List words = Stream.of("bonJour", "bonjour", "Hello")
     .map(str -> str.toLowerCase())
     .distinct()
     .collect(Collectors.toList());
     Étape 2
     

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158. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Structure programmatique
     List words = Stream.of("bonJour", "bonjour", "Hello")
     .map(str -> str.toLowerCase())
     .distinct()
     .collect(Collectors.toList()); Étape 3
     (fonction terminale)
     

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159. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Concept de Monade
     Observable RxJava
     

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160. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Structure programmatique
     Observable.just("bonJour", "bonjour", "Hello")
     .map(str -> str.toLowerCase())
     .distinct()
     .subscribe();
     Factory
     

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161. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Structure programmatique
     Observable.just("bonJour", "bonjour", "Hello")
     .map(str -> str.toLowerCase())
     .distinct()
     .subscribe();
     Étape 1
     

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162. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Structure programmatique
     Observable.just("bonJour", "bonjour", "Hello")
     .map(str -> str.toLowerCase())
     .distinct()
     .subscribe();
     Étape 2
     

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163. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Structure programmatique
     Observable.just("bonJour", "bonjour", "Hello")
     .map(str -> str.toLowerCase())
     .distinct()
     .subscribe(); Étape 3
     (fonction terminale)
     

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164. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Avec les Reactive Extensions,
     nous allons principalement
     manipuler des Observables
     

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165. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Structure programmatique
     Observable
     =
     Monade
     

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166. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Structure programmatique
     Observable
     =
     Programmation
     fonctionnelle
     

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167. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Évitez les effets de bord
     Structure programmatique
     une fonction est dite à effet de bord si elle
     modifie un état autre que sa valeur de retour
     

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168. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Évitez les effets de bord
     Structure programmatique
     une fonction est dite à effet de bord si elle
     modifie un état autre que sa valeur de retour
     (Comme avec les
     streams Java 8)
     

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169. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Question :
     Comment créer une liste
     à partir d’un ensemble
     de valeurs ?
     

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170. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Effets de bord
     List result = new ArrayList<>();
     Observable.just(1, 2, 3)
     .map(i -> result.add(i))
     .subscribe();
     

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171. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     List result = new ArrayList<>();
     Observable.just(1, 2, 3)
     .map(i -> result.add(i))
     .subscribe();
     Effets de bord
     Effet de bord
     

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172. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .toList()
     .subscribe(result -> {/* ... */});
     Effets de bord
     Pas d’effet de bord
     

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173. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .toList()
     .subscribe(result -> {/* ... */});
     Effets de bord
     Consommation de
     la liste
     

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174. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Question :
     Comment logger une
     opération ?
     

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175. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Effets de bord
     Observable.just(1, 2, 3)
     .map(i -> {
     LOGGER.info("value : " + i);
     return i;
     })
     .subscribe();
     

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176. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .map(i -> {
     LOGGER.info("value : " + i);
     return i;
     })
     .subscribe();
     Effets de bord
     Effet de bord
     

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177. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Évitez les effets de bord
     (ou soyez explicite)
     

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178. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Effets de bord
     Observable.just(1, 2, 3)
     // explicite
     .doOnNext(i -> LOGGER.info("Valeur :" + i))
     .subscribe();
     

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179. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Effets de bord
     Observable.just(1, 2, 3)
     .doOnSubscribe(() -> LOGGER.info("Subscribe"))
     .doOnNext(i -> LOGGER.info("Valeur :" + i))
     .doOnTerminate(() -> LOGGER.info("Terminate"))
     .subscribe();
     

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180. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Effets de bord
     Observable.just(1, 2, 3)
     .doOnSubscribe(() -> LOGGER.info("Subscribe"))
     .doOnNext(i -> LOGGER.info("Valeur :" + i))
     .doOnTerminate(() -> LOGGER.info("Terminate"))
     .subscribe();
     

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181. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Effets de bord
     Observable.just(1, 2, 3)
     .doOnSubscribe(() -> LOGGER.info("Subscribe"))
     .doOnNext(i -> LOGGER.info("Valeur :" + i))
     .doOnTerminate(() -> LOGGER.info("Terminate"))
     .subscribe();
     

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182. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Effets de bord
     Observable.just(1, 2, 3)
     .doOnSubscribe(() -> LOGGER.info("Subscribe"))
     .doOnNext(i -> LOGGER.info("Valeur :" + i))
     .doOnTerminate(() -> LOGGER.info("Terminate"))
     .subscribe();
     

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183. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Question :
     Comment compter le
     nombre d’erreur de
     différents Observables ?
     

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184. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     // attention ! état partagé !
     AtomicLong errors = new AtomicLong(0);
     Observable.just(1, 2, 3)
     .doOnError(ex -> errors.incrementAndGet())
     .subscribe();
     

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185. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     // attention ! état partagé !
     AtomicLong errors = new AtomicLong(0);
     Observable.just(1, 2, 3)
     .doOnError(ex -> errors.incrementAndGet())
     .subscribe();
     

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186. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Question :
     Comment créer des
     Observables ?
     

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187. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Comment créer des Observables
     Observable.just()
     Observable.fromCallable()
     Observable.defer()
     Observable.using()
     Observable.create()
     Complexité
     

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188. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Comment créer des Observables
     Observable.just()
     Observable.fromCallable()
     Observable.defer()
     Observable.using()
     Observable.create()
     Simple
     d’utilisation
     

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189. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Comment créer des Observables
     Observable.just()
     Observable.fromCallable()
     Observable.defer()
     Observable.using()
     Observable.create() Complexe
     d’utilisation
     

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190. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Comment créer des Observables
     Observable.just()
     Observable.fromCallable()
     Observable.defer()
     Observable.using()
     Observable.create() Complexe
     d’utilisation
     Offre un maximum de contrôle
     

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191. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Quelle méthode pour
     quelle utilisation ?
     

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192. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(compute())
     .subscribe();
     

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193. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(compute())
     .subscribe();
     

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194. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(compute())
     .subscribe();
     Appelé
     immédiatement
     

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195. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     int result = compute();
     Observable.just(result)
     .subscribe();
     

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196. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     int result = compute();
     Observable.just(result)
     .subscribe();
     

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197. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just permet
     d'émettre une valeur
     déjà existante.
     

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198. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.defer(() -> Observable.just(compute()))
     .subscribe();
     

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199. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.defer(() -> Observable.just(compute()))
     .subscribe();
     

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200. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.defer(() -> Observable.just(compute()))
     .subscribe();
     Création tardive
     

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201. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.defer(() -> Observable.just(compute()))
     .subscribe();
     Création tardive
     Création d’un Observable ?
     

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202. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.defer permet
     de créer tardivement un
     Observable.
     

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203. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.fromCallable(() -> compute())
     .subscribe();
     

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204. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.fromCallable(() -> compute())
     .subscribe();
     Création tardive
     

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205. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.fromCallable
     permet d'émettre
     tardivement une valeur.
     

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206. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.using(
     () -> new DB(),
     db -> Observable.just(db.doQuery()),
     db -> db.closeDb())
     .subscribe();
     

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207. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.using(
     () -> new DB(),
     db -> Observable.just(db.doQuery()),
     db -> db.closeDb())
     .subscribe();
     Création d’une ressource
     

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208. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.using(
     () -> new DB(),
     db -> Observable.just(db.doQuery()),
     db -> db.closeDb())
     .subscribe();
     Émission d’un
     résultat
     

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209. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.using(
     () -> new DB(),
     db -> Observable.just(db.doQuery()),
     db -> db.closeDb())
     .subscribe();
     Fermeture de la
     ressource
     

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210. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.using permet
     d'associer un Observable
     à une ressource.
     

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211. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Attention
     Zone Dangereuse !
     

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212. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.create(subscriber -> {
     subscriber.add(/* ... */);
     subscriber.setProducer(n -> {
     subscriber.onNext(/* ... */);
     // ...
     subscriber.onCompleted();
     });
     }).subscribe();
     

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213. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.create(subscriber -> {
     subscriber.add(/* ... */);
     subscriber.setProducer(n -> {
     subscriber.onNext(/* ... */);
     // ...
     subscriber.onCompleted();
     });
     }).subscribe();
     ?
     ?
     ?
     

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214. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.create(subscriber -> {
     subscriber.add(/* ... */);
     subscriber.setProducer(n -> {
     subscriber.onNext(/* ... */);
     // ...
     subscriber.onCompleted();
     });
     }).subscribe();
     Désabonnement
     Backpressure
     Contrat Rx
     

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215. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.create(subscriber -> {
     subscriber.onNext(compute());
     subscriber.onCompleted();
     }).subscribe();
     

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216. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.create(subscriber -> {
     subscriber.onNext(compute());
     subscriber.onCompleted();
     }).subscribe();
     Contrat Rx
     

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217. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.fromCallable(() -> compute())
     .subscribe();
     Plus simple !
     

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218. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.create(subscriber -> {
     for (int i = 0; i < 10; i++) {
     if (!subscriber.isUnsubscribed()) {
     subscriber.onNext(compute(i));
     }
     }
     subscriber.onCompleted();
     }).subscribe();
     

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219. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.create(subscriber -> {
     for (int i = 0; i < 10; i++) {
     if (!subscriber.isUnsubscribed()) {
     subscriber.onNext(compute(i));
     }
     }
     subscriber.onCompleted();
     }).subscribe();
     Le flux est-il encore
     actif ?
     Éviter de lancer ce
     calcul (coûteux)
     

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220. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.range(1, 10)
     .map(i -> compute(i))
     .subscribe(System.out::println);
     Plus simple !
     

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221. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.create(subscriber -> {
     DB db = new DB();
     subscriber.add(Subscriptions.create(() -> db.closeDb()));
     subscriber.onNext(db);
     subscriber.onCompleted();
     }).subscribe();
     

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222. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.create(subscriber -> {
     DB db = new DB();
     subscriber.add(Subscriptions.create(() -> db.closeDb()));
     subscriber.onNext(db);
     subscriber.onCompleted();
     }).subscribe(); Code de
     désabonnement
     

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223. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.using(
     () -> new DB(),
     db -> Observable.just(db.doQuery()),
     db -> db.closeDb())
     .subscribe();
     Plus simple !
     

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224. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.create
     permet de gérer
     le contrat Rx
     et le désabonnement
     et la backpressure
     

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225. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.create
     vous oblige à gérer
     le contrat Rx
     et le désabonnement
     et la backpressure
     

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226. #DevoxxFR #Rx
     Reactive Extensions
     En pratique
     

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227. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Connaissez vous d’autres
     modèles de concurrence ?
     

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228. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Connaissez vous d’autres modèles de
     concurrence ?
     Non
     Thread
     uniquement
     Oui
     Acteur, STM,
     Channels
     …
     

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229. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Connaissez vous vous d’autres modèles de
     concurrence ?
     Non
     Thread
     uniquement
     

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230. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Connaissez vous vous d’autres modèles de
     concurrence ?
     Oui
     Acteur, STM,
     Channels
     …
     

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231. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Pour explorer
     d’autres
     modèles
     de concurrence
     

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232. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Modèle de concurrence
     

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233. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     On a vu Tomcat et les servlets
     OS
     Tomcat / BIO
     client
     Requête #
     Acceptor
     Thread
     Thread
     war
     

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234. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Modèle de concurrence
     de RxJava
     

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235. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     method() {
     Observable.from(items)
     .map(this::transform)
     .flatMap(this::computeRelativeItems)
     .subscribe(response::resume, response::resume);
     }
     

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236. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     method() {
     Observable.from(items)
     .map(this::transform)
     .flatMap(this::computeRelativeItems)
     .subscribe(response::resume, response::resume);
     }
     Travail sur le
     Thread courant
     

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237. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Par défaut synchrone*
     method() {
     Observable.from(items)
     .map(this::transform)
     .flatMap(this::computeRelativeItems)
     .subscribe(response::resume, response::resume);
     }
     Travail sur le
     Thread courant
     

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238. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxJava permet un contrôle
     explicite de la concurrence
     avec observeOn() ou
     avec subscribeOn()
     

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239. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     method() {
     Observable.from(items)
     .map(this::transform)
     .flatMap(this::computeRelativeItems)
     .subscribe(response::resume, response::resume);
     }
     Thread courant
     

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240. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     method() {
     Observable.from(items)
     .observeOn( )
     .map(this::transform)
     .flatMap(this::computeRelativeItems)
     .subscribe(response::resume, response::resume);
     }
     Thread courant
     

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241. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     method() {
     Observable.from(items)
     .observeOn( )
     .map(this::transform)
     .flatMap(this::computeRelativeItems)
     .subscribe(response::resume, response::resume);
     }
     Thread courant
     

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242. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     method() {
     Observable.from(items)
     .observeOn(Schedulers.computation())
     .map(this::transform)
     .flatMap(this::computeRelativeItems)
     .subscribe(response::resume, response::resume);
     }
     Thread courant
     Travail planifié sur
     computation
     

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243. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     observeOn() change le
     contexte des opérations
     qui suivent
     

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244. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Il peut y avoir plusieurs
     observeOn()
     

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245. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Par défaut synchrone*
     method() {
     Observable.from(items)
     .map(this::transform)
     .delay(10, SECONDS))
     .subscribe(response::resume, response::resume);
     }
     Travail sur le
     Thread courant
     * Certains opérateurs fonctionnent par défaut sur un autre Scheduler
     

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246. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Par défaut synchrone*
     method() {
     Observable.from(items)
     .map(this::transform)
     .delay(10, SECONDS))
     .subscribe(response::resume, response::resume);
     }
     Travail sur le
     Thread courant
     * Certains opérateurs fonctionnent par défaut sur un autre Scheduler
     Change le contexte
     

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247. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Certains opérateurs ont
     le même effet que
     observeOn()
     

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248. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     method() {
     Observable.from(items)
     .observeOn(Schedulers.computation())
     .map(this::transform)
     .flatMap(this::computeRelativeItems)
     .subscribe(response::resume, response::resume);
     }
     Thread courant
     Travail planifié sur
     computation
     

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249. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     method() {
     Observable.from(items)
     .observeOn(Schedulers.computation())
     .map(this::transform)
     .flatMap(this::computeRelativeItems)
     .subscribeOn( )
     .subscribe(response::resume, response::resume);
     }
     Thread courant
     Travail planifié sur
     computation
     

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250. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     method() {
     Observable.from(items)
     .observeOn(Schedulers.computation())
     .map(this::transform)
     .flatMap(this::computeRelativeItems)
     .subscribeOn( )
     .subscribe(response::resume, response::resume);
     }
     Thread courant
     Travail planifié sur
     computation
     

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251. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     method() {
     Observable.from(items)
     .observeOn(Schedulers.computation())
     .map(this::transform)
     .flatMap(this::computeRelativeItems)
     .subscribeOn(Schedulers.io())
     .subscribe(response::resume, response::resume);
     }
     Thread courant
     Travail planifié sur
     computation
     Production des
     éléments sur io
     

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252. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     subscribeOn() définit le
     contexte où s’exécute la
     production des éléments
     

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253. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Il ne peut y avoir
     qu’un seul
     subscribeOn()
     Premier arrivé, premier servi !
     

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254. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     2 principaux modèles de
     schedulers
     

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255. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     computation()
     .map(str -> …) Élément #
     .filter(…)
     Élément <>
     .merge(…)
     Élément ‘a’
     .map(str -> …)
     

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256. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     computation()
     Nombre de
     coeur CPU
     .map(str -> …) Élément #
     .filter(…)
     Élément <>
     .merge(…)
     Élément ‘a’
     .map(str -> …)
     

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257. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     computation()
     Nombre de
     coeur CPU
     .debounce(…)
     .filter(e -> ...)
     .merge(...)
     Élément #
     .filter(…)
     Élément <>
     .merge(…)
     

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258. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Le modèle de
     computation() est une
     boucle d’évènements
     

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259. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Augmente le rendement
     du CPU
     

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260. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Thread.sleep()
     CountDownLatch.await()
     for(;;) { /* do work */ }
     I/O
     

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261. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Thread.sleep()
     CountDownLatch.await()
     for(;;) { /* do work */ }
     I/O
     NON
     

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262. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Ne PAS bloquer
     la boucle d’évènements
     

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263. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     io()
     Élément #
     .filter(…)
     Élément <>
     .merge(…)
     Élément ‘a’
     .flatMap(…)
     

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264. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     io()
     DB
     Élément #
     .filter(…)
     Élément <>
     .merge(…)
     Élément ‘a’
     .flatMap(…)
     

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265. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     io()
     DB
     Élément #
     .filter(…)
     Élément <>
     .merge(…)
     Élément ‘a’
     .flatMap(…)
     

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266. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     io()
     DB
     Network
     Internet
     Élément #
     .filter(…)
     Élément <>
     .merge(…)
     Élément ‘a’
     .flatMap(…)
     

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267. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     io()
     DB
     Network
     Internet
     Élément #
     .filter(…)
     Élément <>
     .merge(…)
     Élément ‘a’
     .flatMap(…)
     

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268. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     io()
     DB
     Network
     Internet
     Élément #
     .filter(…)
     Élément <>
     .merge(…)
     Élément ‘a’
     .flatMap(…)
     

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269. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Le modèle du scheduler
     io() est un pool de thread
     qui grossit au besoin
     

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270. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     io() ne bloque pas le CPU
     

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271. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Avec JAX-RS
     

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272. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @Path("heavy-stuff")
     public static class WaitResource {
     @GET
     @Path("{heavyness}")
     public Response wait(@PathParam("heavyness") int heavyness) throws InterruptedException {
     System.out.format("heavy work that will take %dms%n", heavyness);
     MILLISECONDS.sleep(heavyness); // hard and long work
     return Response.ok(format("Waited %dms", heavyness)).build();
     }
     }
     

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273. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @Path("heavy-stuff")
     public static class WaitResource {
     @GET
     @Path("{heavyness}")
     public Response wait(@PathParam("heavyness") int heavyness) throws InterruptedException {
     System.out.format("heavy work that will take %dms%n", heavyness);
     MILLISECONDS.sleep(heavyness); // hard and long work
     return Response.ok(format("Waited %dms", heavyness)).build();
     }
     }
     Travail
     

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274. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @Path("heavy-stuff")
     public static class WaitResource {
     @GET @Path("{heavyness}")
     public void wait(@Suspended AsyncResponse ar, @PathParam("heavyness") int heavyness) {
     executor.submit(() -> {
     try {
     MILLISECONDS.sleep(heavyness);
     ar.resume(format("Waited %dms", heavyness));
     } catch (InterruptedException e) {
     Thread.interrupted();
     ar.resume(e);
     }
     });
     }
     }
     

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275. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @Path("heavy-stuff")
     public static class WaitResource {
     @GET @Path("{heavyness}")
     public void wait(@Suspended AsyncResponse ar, @PathParam("heavyness") int heavyness) {
     executor.submit(() -> {
     try {
     MILLISECONDS.sleep(heavyness);
     ar.resume(format("Waited %dms", heavyness));
     } catch (InterruptedException e) {
     Thread.interrupted();
     ar.resume(e);
     }
     });
     }
     }
     JAX-RS 2.0 (Servlet 3.0)
     

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276. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @Path("heavy-stuff")
     public static class WaitResource {
     @GET @Path("{heavyness}")
     public void wait(@Suspended AsyncResponse ar, @PathParam("heavyness") int heavyness) {
     executor.submit(() -> {
     try {
     MILLISECONDS.sleep(heavyness);
     ar.resume(format("Waited %dms", heavyness));
     } catch (InterruptedException e) {
     Thread.interrupted();
     ar.resume(e);
     }
     });
     }
     }
     JAX-RS 2.0 (Servlet 3.0)
     Tache
     asynchrone
     

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277. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @Path("heavy-stuff")
     public static class WaitResource {
     @GET @Path("{heavyness}")
     public void wait(@Suspended AsyncResponse ar, @PathParam("heavyness") int heavyness) {
     executor.submit(() -> {
     try {
     MILLISECONDS.sleep(heavyness);
     ar.resume(format("Waited %dms", heavyness));
     } catch (InterruptedException e) {
     Thread.interrupted();
     ar.resume(e);
     }
     });
     }
     }
     JAX-RS 2.0 (Servlet 3.0)
     thread pool
     Tache
     asynchrone
     

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278. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @Path("heavy-stuff")
     public static class WaitResource {
     @GET @Path("{heavyness}")
     public void wait(@Suspended AsyncResponse ar, @PathParam("heavyness") int heavyness) {
     executor.submit(() -> {
     try {
     MILLISECONDS.sleep(heavyness);
     ar.resume(format("Waited %dms", heavyness));
     } catch (InterruptedException e) {
     Thread.interrupted();
     ar.resume(e);
     }
     });
     }
     }
     JAX-RS 2.0 (Servlet 3.0)
     thread pool
     Tache
     asynchrone
     response.resume() pour
     retourner la réponse HTTP
     

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279. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     JAX-RS et Rx
     

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280. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @Path("heavy-stuff")
     public static class WaitResource {
     @GET @Path("{heavyness}")
     public void wait(@Suspended AsyncResponse ar, @PathParam("heavyness") int heavyness) {
     response.setTimeout(50, MILLISECONDS);
     Observable.just(waitTime)
     .observeOn(Schedulers.computation())
     .map(this::longProcess)
     .subscribe(result -> ar.resume(result),
     throwable -> ar.resume(throwable));
     }
     private String longProcess(int heavyness) {
     ...
     }
     }
     

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281. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @Path("heavy-stuff")
     public static class WaitResource {
     @GET @Path("{heavyness}")
     public void wait(@Suspended AsyncResponse ar, @PathParam("heavyness") int heavyness) {
     response.setTimeout(50, MILLISECONDS);
     Observable.just(waitTime)
     .observeOn(Schedulers.computation())
     .map(this::longProcess)
     .subscribe(result -> ar.resume(result),
     throwable -> ar.resume(throwable));
     }
     private String longProcess(int heavyness) {
     ...
     }
     }
     Traitement asynchrone
     avec Rx
     

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282. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @Path("heavy-stuff")
     public static class WaitResource {
     @GET @Path("{heavyness}")
     public void wait(@Suspended AsyncResponse ar, @PathParam("heavyness") int heavyness) {
     response.setTimeout(50, MILLISECONDS);
     Observable.just(waitTime)
     .observeOn(Schedulers.computation())
     .map(this::longProcess)
     .subscribe(result -> ar.resume(result),
     throwable -> ar.resume(throwable));
     }
     private String longProcess(int heavyness) {
     ...
     }
     }
     Prend les paramètres
     

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283. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @Path("heavy-stuff")
     public static class WaitResource {
     @GET @Path("{heavyness}")
     public void wait(@Suspended AsyncResponse ar, @PathParam("heavyness") int heavyness) {
     response.setTimeout(50, MILLISECONDS);
     Observable.just(waitTime)
     .observeOn(Schedulers.computation())
     .map(this::longProcess)
     .subscribe(result -> ar.resume(result),
     throwable -> ar.resume(throwable));
     }
     private String longProcess(int heavyness) {
     ...
     }
     }
     Scheduler sur lequel faire le traitement
     ≈≈> executor
     

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284. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @Path("heavy-stuff")
     public static class WaitResource {
     @GET @Path("{heavyness}")
     public void wait(@Suspended AsyncResponse ar, @PathParam("heavyness") int heavyness) {
     response.setTimeout(50, MILLISECONDS);
     Observable.just(waitTime)
     .observeOn(Schedulers.computation())
     .map(this::longProcess)
     .subscribe(result -> ar.resume(result),
     throwable -> ar.resume(throwable));
     }
     private String longProcess(int heavyness) {
     ...
     }
     }
     Sera exécuté sur
     un Computation thread
     Thread de la servlet
     

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285. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @Path("heavy-stuff")
     public static class WaitResource {
     @GET @Path("{heavyness}")
     public void wait(@Suspended AsyncResponse ar, @PathParam("heavyness") int heavyness) {
     response.setTimeout(50, MILLISECONDS);
     Observable.just(waitTime)
     .observeOn(Schedulers.computation())
     .map(this::longProcess)
     .subscribe(result -> ar.resume(result),
     throwable -> ar.resume(throwable));
     }
     private String longProcess(int heavyness) {
     ...
     }
     }
     Travail
     

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286. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @Path("heavy-stuff")
     public static class WaitResource {
     @GET @Path("{heavyness}")
     public void wait(@Suspended AsyncResponse ar, @PathParam("heavyness") int heavyness) {
     response.setTimeout(50, MILLISECONDS);
     Observable.just(waitTime)
     .observeOn(Schedulers.computation())
     .map(this::longProcess)
     .subscribe(result -> ar.resume(result),
     throwable -> ar.resume(throwable));
     }
     private String longProcess(int heavyness) {
     ...
     }
     }
     onNext : résultat du traitement
     onError : termine la requête HTTP avec une
     erreur
     

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287. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Traitement toujours long
     =
     Attente pour le client
     

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288. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Traitement toujours long
     =
     Attente pour le client
     =
     Toujours besoin de threads
     

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289. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     asyncResponse.setTimeout(50, MILLISECONDS);
     Retourne 503 Service Unavailable
     

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290. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     asyncResponse.setTimeout(50, MILLISECONDS);
     Retourne 503 Service Unavailable
     MAIS le travail en cours est toujours actif
     

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291. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Introduire un TimeoutHandler
     Status HTTP
     Headers
     Entité personnalisée
     Arrêt / interruption des traitements
     ...
     

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292. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     JAX-RS apporte des
     fonctionnalités riches
     mapping, routage, filtre,
     …
     

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293. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     … mais limite
     l’intégration avec RxJava,
     par les contraintes de la
     spec.
     

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294. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     JAX-RS nous limite
     dans notre capacité
     à découpler
     

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295. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Faut-il sortir de la stack
     JavaEE ?
     

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296. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Netflix, Spotify, Twitter,
     Uber, d’autres sont allés
     dans cette direction.
     

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297. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     L’architecture
     microservices est une
     opportunité pour
     explorer les alternatives
     

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298. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Par exemple en Java,
     Vert.x, RxNetty, …
     

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299. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxNetty.createHttpServer(port, (request, response) -> {
     if (request.getHttpMethod() == HttpMethod.POST) {
     return request.getContent()
     .map(TehServer::parseBody)
     .map(TehServer::longStuff)
     .flatMap(result -> {
     response.setStatus(HttpResponseStatus.OK);
     response.writeString(result);
     return response.close();
     }).ignoreElements();
     }
     return response.close(false);
     });
     

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300. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxNetty.createHttpServer(port, (request, response) -> {
     if (request.getHttpMethod() == HttpMethod.POST) {
     return request.getContent()
     .map(TehServer::parseBody)
     .map(TehServer::longStuff)
     .flatMap(result -> {
     response.setStatus(HttpResponseStatus.OK);
     response.writeString(result);
     return response.close();
     }).ignoreElements();
     }
     return response.close(false);
     });
     Créer un serveur
     

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301. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxNetty.createHttpServer(port, (request, response) -> {
     if (request.getHttpMethod() == HttpMethod.POST) {
     return request.getContent()
     .map(TehServer::parseBody)
     .map(TehServer::longStuff)
     .flatMap(result -> {
     response.setStatus(HttpResponseStatus.OK);
     response.writeString(result);
     return response.close();
     }).ignoreElements();
     }
     return response.close(false);
     });
     Handler pour gérer
     la requête
     

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302. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxNetty.createHttpServer(port, (request, response) -> {
     if (request.getHttpMethod() == HttpMethod.POST) {
     return request.getContent()
     .map(TehServer::parseBody)
     .map(TehServer::longStuff)
     .flatMap(result -> {
     response.setStatus(HttpResponseStatus.OK);
     response.writeString(result);
     return response.close();
     }).ignoreElements();
     }
     return response.close(false);
     });
     Retourne un Observable
     

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303. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxNetty.createHttpServer(port, (request, response) -> {
     if (request.getHttpMethod() == HttpMethod.POST) {
     return request.getContent()
     .map(TehServer::parseBody)
     .map(TehServer::longStuff)
     .flatMap(result -> {
     response.setStatus(HttpResponseStatus.OK);
     response.writeString(result);
     return response.close();
     }).ignoreElements();
     }
     return response.close(false);
     });
     Travail sur la request
     avec RxJava
     

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304. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxNetty s’utilise pour
     des services très simples
     websocket, http, tcp, …
     

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305. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxNetty intégre RxJava
     au plus bas niveau
     

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306. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Un main() seulement
     

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307. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxNetty offre une API de
     bas niveau pour plus
     de contrôle
     

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308. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     … mais demande un effort
     appréciable sur la mise en
     oeuvre des aspects d’une
     API HTTP publique
     

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309. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Services composés
     

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310. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Composite
     API
     Service B
     Service A
     

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311. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Composite
     API
     

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312. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     }
     Exemple : un stub JAX-RS
     

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313. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     Observable.fromCallable(() -> makeInterestingValue())
     .subscribe(response::resume);
     }
     Un Observable qui
     renvoie quelque chose
     sur AsyncResponse
     

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314. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     Observable.fromCallable(() -> makeInterestingValue())
     .flatMap(lastNumber -> {
     …
     })
     .subscribe(response::resume);
     }
     Ici seront fait les appels
     

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315. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Composite
     API
     Service A
     

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316. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     Observable.fromCallable(() -> makeInterestingValue())
     .flatMap(lastNumber -> {
     Response aResponse = wsA(lastNumber);
     …
     })
     .subscribe(response::resume);
     }
     Appel
     au service A
     

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317. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     Observable.fromCallable(() -> makeInterestingValue())
     .flatMap(lastNumber -> {
     Observable aObs =
     Observable.fromCallable(() -> wsA(lastNumber));
     …
     })
     .subscribe(response::resume);
     }
     Appel
     observable
     au service A
     

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318. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     Observable.fromCallable(() -> makeInterestingValue())
     .flatMap(lastNumber -> {
     Observable aObs =
     Observable.fromCallable(() -> wsA(lastNumber))
     .map(r -> r.readEntity(String.class));
     …
     })
     .subscribe(response::resume);
     }
     Transformation
     de la payload
     

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319. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Composite
     API
     Service B
     Service A
     

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320. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     Observable.fromCallable(() -> makeInterestingValue())
     .flatMap(lastNumber -> {
     Observable aObs = Observable.fromCallable(() -> wsA(lastNumber))
     .map(r -> r.readEntity(String.class));
     Observable bObs =
     Observable.fromCallable(() -> wsB(lastNumber))
     .map(r -> r.readEntity(String.class));
     …
     })
     .subscribe(response::resume);
     }
     Appel observable
     au service B
     

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321. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Composite
     API
     Service B
     Service A
     

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322. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     Observable.fromCallable(() -> makeInterestingValue())
     .flatMap(lastNumber -> {
     Observable aObs = Observable.fromCallable(() -> wsA(lastNumber))
     .map(r -> r.readEntity(String.class));
     Observable bObs = Observable.fromCallable(() -> wsB(lastNumber))
     .map(r -> r.readEntity(String.class));
     return Observable.zip(aObs, bObs,
     (a, b) -> format("=> Result : %s, %s", a, b);
     })
     .subscribe(response::resume);
     }
     Composition
     de A et de B
     

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323. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Si une exception est
     produite ?
     

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324. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     Observable.fromCallable(() -> makeInterestingValue())
     .flatMap(lastNumber -> {
     Observable aObs = Observable.fromCallable(() -> wsA(lastNumber))
     .map(r -> r.readEntity(String.class));
     Observable bObs = Observable.fromCallable(() -> wsB(lastNumber))
     .map(r -> r.readEntity(String.class));
     return Observable.zip(aObs, bObs, (a, b) -> format("=> Result : %s, %s", a, b);
     })
     .subscribe(response::resume,
     response::resume);
     }
     Ajout d’un handler onError
     

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325. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Planifier les appels
     externes sur
     Schedulers.io()
     

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326. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     Observable.fromCallable(() -> makeInterestingValue())
     .flatMap(lastNumber -> {
     Observable aObs = Observable.fromCallable(() -> wsA(lastNumber))
     .subscribeOn(Schedulers.io())
     .map(r -> r.readEntity(String.class));
     Observable bObs = Observable.fromCallable(() -> wsB(lastNumber))
     .subscribeOn(Schedulers.io())
     .map(r -> r.readEntity(String.class));
     return Observable.zip(aObs, bObs, (a, b) -> format("=> Result : %s, %s", a, b);
     })
     .subscribe(response::resume,
     response::resume);
     }
     Appels réseau
     exécutés sur
     des threads dédiés
     aux I/O
     

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327. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Composite
     API
     Service B
     Service A
     503
     

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328. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     Observable.fromCallable(() -> makeInterestingValue())
     .flatMap(lastNumber -> {
     Observable aObs = Observable.fromCallable(() -> wsA(lastNumber))
     .subscribeOn(Schedulers.io())
     .flatMap(r -> {
     if (r.getStatus() == 503) {
     return Observable.error(
     new ServiceUnavailable("service A"));
     }
     return just(r.readEntity(String.class));
     });
     Observable bObs = Observable.fromCallable(() -> wsB(lastNumber))
     .subscribeOn(Schedulers.io())
     .map(r -> r.readEntity(String.class));
     return Observable.zip(aObs, bObs, (a, b) -> format("=> Result : %s, %s", a, b);
     })
     .subscribe(response::resume,
     response::resume);
     }
     Gestion du statut HTTP 503
     

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329. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     Observable.fromCallable(() -> makeInterestingValue())
     .flatMap(lastNumber -> {
     Observable aObs = Observable.fromCallable(() -> wsServiceA(lastNumber))
     .subscribeOn(Schedulers.io())
     .flatMap(r -> {
     if (r.getStatus() != 200) {
     return Observable.error(
     new ServiceUnavailable("service A"));
     }
     return Observable.just(r.readEntity(String.class));
     });
     Observable bObs = Observable.fromCallable(() -> wsServiceB(lastNumber))
     .subscribeOn(Schedulers.io())
     .map(r -> r.readEntity(String.class));
     return Observable.zip(aObs, bObs, (a, b) -> format("=> Result : %s, %s", a, b);
     })
     .subscribe(response::resume,
     (error) -> {
     response.resume(error);
     });
     }
     AsyncReponse.resume(Throwable)
     ⇒ 500 Server Error
     

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330. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     Observable.fromCallable(() -> makeInterestingValue())
     .flatMap(lastNumber -> {
     Observable aObs = Observable.fromCallable(() -> wsServiceA(lastNumber))
     .subscribeOn(Schedulers.io())
     .flatMap(r -> {
     if (r.getStatus() != 200) {
     return Observable.error(new ServiceUnavailable("service A"));
     }
     return Observable.just(r.readEntity(String.class));
     });
     Observable bObs = Observable.fromCallable(() -> wsServiceB(lastNumber))
     .subscribeOn(Schedulers.io())
     .map(r -> r.readEntity(String.class));
     return Observable.zip(aObs, bObs, (a, b) -> format("=> Result : %s, %s", a, b);
     })
     .subscribe(response::resume,
     (error) -> {
     response.resume(Response.serverError()
     .entity(error.getMessage())
     .build());
     });
     }
     Personnalisation de la
     payload d’erreur
     

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331. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     Observable.fromCallable(() -> makeInterestingValue())
     .flatMap(lastNumber -> {
     Observable aObs = Observable.fromCallable(() -> wsServiceA(lastNumber))
     .subscribeOn(Schedulers.io())
     .flatMap(r -> {
     if (r.getStatus() != 200) {
     return Observable.error(new ServiceUnavailable("service A"));
     }
     return Observable.just(r.readEntity(String.class));
     });
     Observable bObs = Observable.fromCallable(() -> wsServiceB(lastNumber))
     .subscribeOn(Schedulers.io())
     .map(r -> r.readEntity(String.class));
     return Observable.zip(aObs, bObs, (a, b) -> format("=> Result : %s, %s", a, b);
     })
     .subscribe(response::resume,
     (error) -> {
     response.resume(Response.status(((HttpServiceEx) error).httpStatus)
     .entity(error.getMessage())
     .build());
     });
     }
     Propagation du statut HTTP
     

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332. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Recommencer
     l’appel en cas d’erreur ?
     

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333. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     Observable.fromCallable(() -> makeInterestingValue())
     .flatMap(lastNumber -> {
     Observable aObs = Observable.fromCallable(() -> wsServiceA(lastNumber))
     .subscribeOn(Schedulers.io())
     .flatMap(r -> {
     if (r.getStatus() != 200) {
     return Observable.error(new ServiceUnavailable("service A"));
     }
     return Observable.just(r.readEntity(String.class));
     })
     .retry(2);
     Observable bObs = Observable.fromCallable(() -> wsServiceB(lastNumber))
     .subscribeOn(Schedulers.io())
     .map(r -> r.readEntity(String.class));
     return Observable.zip(aObs, bObs, (a, b) -> format("=> Result : %s, %s", a, b);
     })
     .subscribe(response::resume,
     (error) -> {
     response.resume(Response.status(((HttpServiceException) error).proposedHttpStatus)
     .entity(error.getMessage())
     .build());
     });
     }
     Recommencera 2 fois
     

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334. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Quand une dépendance
     est hors-délai ?
     

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335. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Composite
     API
     Service B
     Service A
     Service B
     

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336. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     Observable.fromCallable(() -> makeValue())
     .flatMap(lastNumber -> {
     Observable aObs = Observable.fromCallable(() -> wsServiceA(lastNumber))
     .subscribeOn(Schedulers.io())
     .flatMap(r -> {
     if (r.getStatus() != 200) {
     return Observable.error(new ServiceUnavailable("service A"));
     }
     return Observable.just(r.readEntity(String.class));
     })
     .retry(2);
     Observable bObs = Observable.fromCallable(() -> wsServiceB(lastNumber))
     .subscribeOn(Schedulers.io())
     .map(r -> r.readEntity(String.class))
     .timeout(500, MILLISECONDS,
     error(new ServiceTimeout("service B")));
     return Observable.zip(aObs, bObs, (a, b) -> format("=> Result : %s, %s", a, b);
     })
     .subscribe(response::resume,
     (error) -> {
     response.resume(Response.status(((HttpServiceException) error).proposedHttpStatus)
     .entity(error.getMessage())
     .build());
     });
     }
     Défini un délai acceptable
     

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337. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     C’est beaucoup
     de code technique !
     

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338. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Hystrix permet
     de résoudre
     ces challenges
     de façon plus pertinente
     

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339. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     Observable.fromCallable(() -> new SecureRandom().nextInt(1000))
     .flatMap(lastNumber -> {
     Observable aObs = new ServiceACommand(lastNumber).observe();
     Observable bObs = new ServiceBCommand(lastNumber).observe();
     return Observable.zip(aObs, bObs, (a, b) -> format("=> Result : %s, %s", a, b);
     })
     .subscribe(response::resume,
     (error) -> {
     response.resume(Response.statusError()
     .entity(error.getMessage())
     .build());
     });
     }
     Commandes Hystrix
     

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340. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Exécution immédiate et
     asynchrone avec
     .observe()
     Hot
     

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341. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Exécution retardée jusqu’à
     l'abonnement avec
     .toObservable()
     Cold
     

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342. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Une commande Hystrix
     ne doit jamais partir
     en erreur
     

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343. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     @GET public void wait(@Suspended final AsyncResponse response) {
     Observable.fromCallable(() -> new SecureRandom().nextInt(1000))
     .flatMap(lastNumber -> {
     Observable aObs = new ServiceACommand(lastNumber).observe();
     Observable bObs = new ServiceBCommand(lastNumber).observe();
     return Observable.zip(aObs, bObs, (a, b) -> format("=> Result : %s, %s", a, b);
     })
     .subscribe(response::resume,
     (error) -> {
     response.resume(Response.serverError()
     .entity(error.getMessage())
     .build());
     });
     }
     Erreur 500
     

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344. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     class ServiceACommand extends HystrixObservableCommand {
     private int number;
     protected ServiceACommand(int number) {
     super(Setter.withGroupKey(HystrixCommandGroupKey.Factory.asKey("work group"))
     .andCommandKey(HystrixCommandKey.Factory.asKey("work"))
     .andCommandPropertiesDefaults(
     HystrixCommandProperties.Setter().withExecutionTimeoutInMilliseconds(500)));
     this.number = number;
     }
     @Override
     protected Observable construct() {
     return Observable.fromCallable(() -> wsServiceB(number))
     .map(response -> response.readEntity(String.class));
     }
     @Override
     protected Observable resumeWithFallback() {
     return Observable.just("Service A too long");
     }
     }
     

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345. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     class ServiceACommand extends HystrixObservableCommand {
     private int number;
     protected ServiceACommand(int number) {
     super(Setter.withGroupKey(HystrixCommandGroupKey.Factory.asKey("work group"))
     .andCommandKey(HystrixCommandKey.Factory.asKey("work"))
     .andCommandPropertiesDefaults(
     HystrixCommandProperties.Setter().withExecutionTimeoutInMilliseconds(500)));
     this.number = number;
     }
     @Override
     protected Observable construct() {
     return Observable.fromCallable(() -> wsServiceB(number))
     .map(response -> response.readEntity(String.class));
     }
     @Override
     protected Observable resumeWithFallback() {
     return Observable.just("Service A too long");
     }
     }
     Commande Hystrix
     Type de retour
     

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346. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     class ServiceACommand extends HystrixObservableCommand {
     private int number;
     protected ServiceACommand(int number) {
     super(Setter.withGroupKey(HystrixCommandGroupKey.Factory.asKey("work group"))
     .andCommandKey(HystrixCommandKey.Factory.asKey("work"))
     .andCommandPropertiesDefaults(
     HystrixCommandProperties.Setter().withExecutionTimeoutInMilliseconds(500)));
     this.number = number;
     }
     @Override
     protected Observable construct() {
     return Observable.fromCallable(() -> wsServiceB(number))
     .map(response -> response.readEntity(String.class));
     }
     @Override
     protected Observable resumeWithFallback() {
     return Observable.just("Service A too long");
     }
     }
     Commande Hystrix
     observable
     Construction
     

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347. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     class ServiceACommand extends HystrixObservableCommand {
     private int number;
     protected ServiceACommand(int number) {
     super(Setter.withGroupKey(HystrixCommandGroupKey.Factory.asKey("work group"))
     .andCommandKey(HystrixCommandKey.Factory.asKey("work"))
     .andCommandPropertiesDefaults(
     HystrixCommandProperties.Setter().withExecutionTimeoutInMilliseconds(500)));
     this.number = number;
     }
     @Override
     protected Observable construct() {
     return Observable.fromCallable(() -> wsServiceB(number))
     .map(response -> response.readEntity(String.class));
     }
     @Override
     protected Observable resumeWithFallback() {
     return Observable.just("Service A too long");
     }
     }
     Appel observable
     

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348. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     class ServiceACommand extends HystrixObservableCommand {
     private int number;
     protected ServiceACommand(int number) {
     super(Setter.withGroupKey(HystrixCommandGroupKey.Factory.asKey("work group"))
     .andCommandKey(HystrixCommandKey.Factory.asKey("work"))
     .andCommandPropertiesDefaults(
     HystrixCommandProperties.Setter().withExecutionTimeoutInMilliseconds(500)));
     this.number = number;
     }
     @Override
     protected Observable construct() {
     return Observable.fromCallable(() -> wsServiceB(number))
     .map(response -> response.readEntity(String.class));
     }
     @Override
     protected Observable resumeWithFallback() {
     return Observable.just("Service A too long");
     }
     }
     Plan de secours
     En cas d’erreur
     

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349. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     class ServiceACommand extends HystrixObservableCommand {
     private int number;
     protected ServiceACommand(int number) {
     super(Setter.withGroupKey(HystrixCommandGroupKey.Factory.asKey("work group"))
     .andCommandKey(HystrixCommandKey.Factory.asKey("work"))
     .andCommandPropertiesDefaults(
     HystrixCommandProperties.Setter().withExecutionTimeoutInMilliseconds(500)));
     this.number = number;
     }
     @Override
     protected Observable construct() {
     return Observable.fromCallable(() -> wsServiceB(number))
     .map(response -> response.readEntity(String.class));
     }
     @Override
     protected Observable resumeWithFallback() {
     return Observable.just("Service A too long");
     }
     }
     Personnalisation des paramètres
     de la commande
     

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350. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Le coupe-circuit de
     Hystrix
     

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351. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Composite
     API
     Service B
     Service A
     

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352. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Fermé, les requêtes
     passent
     

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353. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Ouvert, la dépendance
     en erreur est isolée sur
     une période de temps
     

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354. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Avertir un client lorsque
     le circuit est ouvert
     

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355. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     void executeCommand(HystrixObservableCommand command) {
     command.observe()
     .subscribe(
     result -> Response.ok(result).build(),
     throwable -> {
     if (throwable instanceof HystrixRuntimeException) {
     if (((HystrixRuntimeException) throwable).getFailureType() == FailureType.SHORTCIRCUIT) {
     Response.status(Status.SERVICE_UNAVAILABLE)
     .header(HttpHeaders.RETRY_AFTER,
     command.getProperties()
     .circuitBreakerSleepWindowInMilliseconds()
     .get() / 1000);
     }
     }
     Response.serverError().build();
     });
     }
     Pour une commande Hystrix
     

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356. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     void executeCommand(HystrixObservableCommand command) {
     command.observe()
     .subscribe(
     result -> Response.ok(result).build(),
     throwable -> {
     if (throwable instanceof HystrixRuntimeException) {
     if (((HystrixRuntimeException) throwable).getFailureType() == FailureType.SHORTCIRCUIT) {
     Response.status(Status.SERVICE_UNAVAILABLE)
     .header(HttpHeaders.RETRY_AFTER,
     command.getProperties()
     .circuitBreakerSleepWindowInMilliseconds()
     .get() / 1000);
     }
     }
     Response.serverError().build();
     });
     }
     Si le problème vient de la
     commande Hystrix
     

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357. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     private void executeCommand(HystrixObservableCommand command) {
     command.observe()
     .subscribe(
     result -> Response.ok(result).build(),
     throwable -> {
     if (throwable instanceof HystrixRuntimeException) {
     if (((HystrixRuntimeException) throwable).getFailureType()
     == FailureType.SHORTCIRCUIT) {
     Response.status(Status.SERVICE_UNAVAILABLE)
     .header(HttpHeaders.RETRY_AFTER,
     command.getProperties()
     .circuitBreakerSleepWindowInMilliseconds()
     .get() / 1000);
     }
     }
     Response.serverError().build();
     });
     }
     Et que le circuit est ouvert
     

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358. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     private void executeCommand(HystrixObservableCommand command) {
     command.observe()
     .subscribe(
     result -> Response.ok(result).build(),
     throwable -> {
     if (throwable instanceof HystrixRuntimeException) {
     if (((HystrixRuntimeException) throwable).getFailureType() == FailureType.SHORTCIRCUIT) {
     Response.status(Status.SERVICE_UNAVAILABLE)
     .header(HttpHeaders.RETRY_AFTER,
     command.getProperties()
     .circuitBreakerSleepWindowInMilliseconds()
     .get() / 1000);
     }
     }
     Response.serverError().build();
     });
     }
     Alors
     proposer au client un prochain créneau
     

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359. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     private void executeCommand(HystrixObservableCommand command) {
     command.observe()
     .subscribe(
     result -> Response.ok(result).build(),
     throwable -> {
     if (throwable instanceof HystrixRuntimeException) {
     if (((HystrixRuntimeException) throwable).getFailureType() == FailureType.SHORTCIRCUIT) {
     Response.status(Status.SERVICE_UNAVAILABLE)
     .header(HttpHeaders.RETRY_AFTER,
     command.getProperties()
     .circuitBreakerSleepWindowInMilliseconds()
     .get() / 1000);
     }
     }
     Response.serverError().build();
     });
     }
     

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360. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Hystrix demande une
     certaine dose de code
     Il est possible d’utiliser
     des annotations avec
     hystrix-javanica
     

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361. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     

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362. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Hystrix protège un
     système distribué de
     dépendances en erreur
     ou hors-délai
     

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363. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Hystrix offre
     une variété d’outils
     

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364. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     

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365. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Autre piste à explorer
     

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366. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Pression arrière
     

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367. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Production
     Consommation
     

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368. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Producteur Consommateur ?
     

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369. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Producteur Consommateur ?
     

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370. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Consommation
     .buffer()
     Production
     

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371. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Consommation
     .sample()
     Production
     

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372. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Consommation
     Isolation du
     consommateur
     Production
     

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373. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Consommation
     Pression arrière
     Isolation du
     consommateur
     Production
     

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374. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     C’est le temps d’une pause
     Posez nous des questions
     directement ou via Twitter
     

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375. #DevoxxFR #Rx
     Reactive Extensions
     Sur notre application
     

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376. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Leçons apprises
     en utilisant les
     Reactive Extensions ?
     

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377. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxJava est-il
     la solution à tout ?
     

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378. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxJava est-il
     la solution à tout ?
     NON !
     

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379. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Les Streams Java 8
     peuvent être plus
     intéressants.
     

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380. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Il est possible
     de faire cohabiter
     RxJava et Streams Java8
     

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381. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3, 4)
     .toList()
     .map(list -> {
     return list.stream()
     .filter(i -> i % 2 == 0)
     .collect(Collectors.toList());
     }).subscribe();
     

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382. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3, 4)
     .toList()
     .map(list -> {
     return list.stream()
     .filter(i -> i % 2 == 0)
     .collect(Collectors.toList());
     }).subscribe();
     

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383. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3, 4)
     .toList()
     .map(list -> {
     return list.stream()
     .filter(i -> i % 2 == 0)
     .collect(Collectors.toList());
     }).subscribe();
     

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384. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     List> obs = new ArrayList<>();
     obs.add(Observable.defer(() -> Observable.just(1, 2, 3)));
     obs.add(Observable.just(4, 5, 6));
     obs.add(Observable.fromCallable(() -> 7));
     Observable.merge(obs).subscribe();
     

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385. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     List> obs = new ArrayList<>();
     obs.add(Observable.defer(() -> Observable.just(1, 2, 3)));
     obs.add(Observable.just(4, 5, 6));
     obs.add(Observable.fromCallable(() -> 7));
     Observable.merge(obs).subscribe();
     

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386. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     List> obs = new ArrayList<>();
     obs.add(Observable.defer(() -> Observable.just(1, 2, 3)));
     obs.add(Observable.just(4, 5, 6));
     obs.add(Observable.fromCallable(() -> 7));
     Observable.merge(obs).subscribe();
     

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387. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     List> obs = new ArrayList<>();
     obs.add(Observable.defer(() -> Observable.just(1, 2, 3)));
     obs.add(Observable.just(4, 5, 6));
     obs.add(Observable.fromCallable(() -> 7));
     Observable.merge(obs).subscribe();
     

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388. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Ce n’est pas parce
     que l’on peut le faire
     que l’on doit le faire.
     

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389. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable feeds = Observable.merge(
     services.stream()
     .map(service -> service.newRequest().user(user).all().observe())
     .map(feedObservable -> feedObservable
     .doOnError(throwable -> log.error(throwable.getMessage(), throwable))
     .onErrorResumeNext(Observable.empty()))
     .collect(Collectors.toList()));
     feeds.subscribe();
     

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390. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable feeds = Observable.merge(
     services.stream()
     .map(service -> service.newRequest().user(user).all().observe())
     .map(feedObservable -> feedObservable
     .doOnError(throwable -> log.error(throwable.getMessage(), throwable))
     .onErrorResumeNext(Observable.empty()))
     .collect(Collectors.toList()));
     feeds.subscribe();
     RxJava
     Stream Java 8
     

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391. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Les lambdas simplifient
     la lecture du code
     

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392. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxView.clickEvents(tapButton)
     .doOnNext(new Action1() {
     @Override
     public void call(ViewClickEvent onClickEvent) {
     LOGGER.debug("--------- GOT A TAP");
     }
     })
     .map(new Func1() {
     @Override
     public Integer call(ViewClickEvent onClickEvent) {
     return 1;
     }
     }).subscribe();
     

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393. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxView.clickEvents(tapButton)
     .doOnNext(new Action1() {
     @Override
     public void call(ViewClickEvent onClickEvent) {
     LOGGER.debug("--------- GOT A TAP");
     }
     })
     .map(new Func1() {
     @Override
     public Integer call(ViewClickEvent onClickEvent) {
     return 1;
     }
     }).subscribe();
     Code technique
     

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394. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxView.clickEvents(tapButton)
     .doOnNext(event -> LOGGER.debug("--------- GOT A TAP"))
     .map(event -> 1)
     .subscribe();
     3 fois moins de code !
     

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395. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Sur Android,
     vous pouvez utiliser
     Kotlin ou Retrolambda
     ou Java 8 (Jack&Jill)
     

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396. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     https://twitter.com/Piwai/status/717755657106001921
     

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397. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .flatMap(i -> {
     Observable complex = webService.complexify(i)
     .map(str -> str.toLowerCase())
     .retry(4);
     Observable human = webService.toHumanString(i)
     .filter(str -> str.length() < 3)
     .take(1)
     .onErrorResumeNext(Observable.empty())
     .defaultIfEmpty("Oups !");
     return Observable.zip(complex, human, (c, h) -> c + h)
     .flatMap(str -> webService.frequencyOf(str))
     .flatMapIterable(itr -> itr);
     }).subscribe();
     

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398. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .flatMap(i -> {
     Observable complex = webService.complexify(i)
     .map(str -> str.toLowerCase())
     .retry(4);
     Observable human = webService.toHumanString(i)
     .filter(str -> str.length() < 3)
     .take(1)
     .onErrorResumeNext(Observable.empty())
     .defaultIfEmpty("Oups !");
     return Observable.zip(complex, human, (c, h) -> c + h)
     .flatMap(str -> webService.frequencyOf(str))
     .flatMapIterable(itr -> itr);
     }).subscribe();
     

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399. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .flatMap(i -> {
     Observable complex = webService.complexify(i)
     .map(str -> str.toLowerCase())
     .retry(4);
     Observable human = webService.toHumanString(i)
     .filter(str -> str.length() < 3)
     .take(1)
     .onErrorResumeNext(Observable.empty())
     .defaultIfEmpty("Oups !");
     return Observable.zip(complex, human, (c, h) -> c + h)
     .flatMap(str -> webService.frequencyOf(str))
     .flatMapIterable(itr -> itr);
     }).subscribe();
     

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400. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .flatMap(i -> {
     Observable complex = webService.complexify(i)
     .map(str -> str.toLowerCase())
     .retry(4);
     Observable human = webService.toHumanString(i)
     .filter(str -> str.length() < 3)
     .take(1)
     .onErrorResumeNext(Observable.empty())
     .defaultIfEmpty("Oups !");
     return Observable.zip(complex, human, (c, h) -> c + h)
     .flatMap(str -> webService.frequencyOf(str))
     .flatMapIterable(itr -> itr);
     }).subscribe();
     

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401. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .flatMap(i -> {
     Observable complex = webService.complexify(i)
     .map(str -> str.toLowerCase())
     .retry(4);
     Observable human = webService.toHumanString(i)
     .filter(str -> str.length() < 3)
     .take(1)
     .onErrorResumeNext(Observable.empty())
     .defaultIfEmpty("Oups !");
     return Observable.zip(complex, human, (c, h) -> c + h)
     .flatMap(str -> webService.frequencyOf(str))
     .flatMapIterable(itr -> itr);
     }).subscribe();
     

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402. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .flatMap(i -> {
     Observable complex = webService.complexify(i)
     .map(str -> str.toLowerCase())
     .retry(4);
     Observable human = webService.toHumanString(i)
     .filter(str -> str.length() < 3)
     .take(1)
     .onErrorResumeNext(Observable.empty())
     .defaultIfEmpty("Oups !");
     return Observable.zip(complex, human, (c, h) -> c + h)
     .flatMap(str -> webService.frequencyOf(str))
     .flatMapIterable(itr -> itr);
     }).subscribe();
     Trop complexe !
     

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403. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .flatMap(i -> {
     Observable complex = webService.complexify(i)
     .map(str -> str.toLowerCase())
     .retry(4);
     Observable human = webService.toHumanString(i)
     .filter(str -> str.length() < 3)
     .take(1)
     .onErrorResumeNext(Observable.empty())
     .defaultIfEmpty("Oups !");
     return Observable.zip(complex, human, (c, h) -> c + h)
     .flatMap(str -> webService.frequencyOf(str))
     .flatMapIterable(itr -> itr);
     }).subscribe();
     Extraction
     

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404. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .flatMap(i -> transform(i))
     .subscribe();
     public Observable transform(int i) {
     Observable complex = webService.complexify(i)
     .map(str -> str.toLowerCase())
     .retry(4);
     Observable human = webService.toHumanString(i)
     .filter(str -> str.length() < 3)
     .take(1)
     .onErrorResumeNext(Observable.empty())
     .defaultIfEmpty("Oups !");
     return Observable.zip(complex, human, (c, h) -> c + h)
     .flatMap(str -> webService.frequencyOf(str))
     .flatMapIterable(itr -> itr);
     }
     

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405. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .flatMap(i -> transform(i))
     .subscribe();
     public Observable transform(int i) {
     Observable complex = fetchComplexify(i);
     Observable human = fetchHuman(i);
     return Observable.zip(complex, human, (c, h) -> c + h)
     .flatMap(str -> webService.frequencyOf(str))
     .flatMapIterable(itr -> itr)
     }
     

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406. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Ne quittez pas la monade !
     (grossièrement)
     

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407. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Ne quittez pas la monade !
     Observable.just(1, 2, 3)
     .subscribe(arg -> {
     webservice.call(arg).subscribe(System.out::println);
     });
     

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408. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.just(1, 2, 3)
     .subscribe(arg -> {
     webservice.call(arg).subscribe(System.out::println);
     });
     Ne quittez pas la monade !
     Observable imbriqué
     

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409. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Ne quittez pas la monade !
     Observable.just(1, 2, 3)
     .flatMap(arg -> webservice.call(arg))
     .subscribe(System.out::println);
     

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410. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Ne quittez pas la monade !
     Observable.just(1, 2, 3)
     .flatMap(arg -> webservice.call(arg))
     .subscribe(System.out::println);
     

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411. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     flatMap permet
     d'émettre zéro, un,
     ou plusieurs évènements
     

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412. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .flatMap(tps -> Observable.just(1, 2, 3))
     .subscribe(System.out::println);
     

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413. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .flatMap(tps -> Observable.just(1, 2, 3))
     .subscribe(System.out::println);
     

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414. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .flatMap(tps -> Observable.just(1, 2, 3))
     .subscribe(System.out::println);
     

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415. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     flatMap ne remplace pas
     un Observable par un
     autre.
     

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416. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .flatMap(tps -> Observable.just(1, 2, 3))
     .subscribe(System.out::println,
     Throwable::printStackTrace,
     () -> System.out.println("Completed !"));
     

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417. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .flatMap(tps -> Observable.just(1, 2, 3))
     .subscribe(System.out::println,
     Throwable::printStackTrace,
     () -> System.out.println("Completed !"));
     

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418. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .flatMap(tps -> Observable.just(1, 2, 3))
     .subscribe(System.out::println,
     Throwable::printStackTrace,
     () -> System.out.println("Completed !"));
     

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419. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .flatMap(tps -> Observable.just(1, 2, 3))
     .subscribe(System.out::println,
     Throwable::printStackTrace,
     () -> System.out.println("Completed !"));
     

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420. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .flatMap(tps -> Observable.just(1, 2, 3))
     .subscribe(System.out::println,
     Throwable::printStackTrace,
     () -> System.out.println("Completed !"));
     

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421. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .flatMap(tps -> Observable.just(1, 2, 3))
     .subscribe(System.out::println,
     Throwable::printStackTrace,
     () -> System.out.println("Completed !"));
     Cela n’arrivera
     jam
     ais !
     

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422. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Il faut comprendre
     le contrat Rx
     pour comprendre
     les opérateurs
     

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423. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .toList()
     .subscribe(System.out::println);
     

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424. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .toList()
     .subscribe(System.out::println);
     

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425. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .toList()
     .subscribe(System.out::println);
     

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426. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     toList()
     toList()
     

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427. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     toList()
     toList()
     

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428. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval
     

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429. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval
     Fin du flux ?
     

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430. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .toList()
     .subscribe(System.out::println);
     

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431. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Hot versus Cold
     

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432. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Un Cold Observable créé
     l'émetteur
     

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433. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Un Hot Observable
     utilise un émetteur
     existant
     

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434. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.create(subscriber -> {
     Timer timer = new Timer();
     timer.onTick(() -> subscriber.onNext("tick"));
     }).subscribe();
     

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435. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.create(subscriber -> {
     Timer timer = new Timer();
     timer.onTick(() -> subscriber.onNext("tick"));
     }).subscribe();
     

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436. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.create(subscriber -> {
     Timer timer = new Timer();
     timer.onTick(() -> subscriber.onNext("tick"));
     }).subscribe();
     

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437. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.create(subscriber -> {
     Timer timer = new Timer();
     timer.onTick(() -> subscriber.onNext("tick"));
     }).subscribe();
     Cold
     

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438. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Timer timer = new Timer();
     Observable.create(subscriber -> {
     timer.onTick(() -> subscriber.onNext("tick"));
     }).subscribe();
     

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439. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Timer timer = new Timer();
     Observable.create(subscriber -> {
     timer.onTick(() -> subscriber.onNext("tick"));
     }).subscribe();
     

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440. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Timer timer = new Timer();
     Observable.create(subscriber -> {
     timer.onTick(() -> subscriber.onNext("tick"));
     }).subscribe();
     

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441. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Timer timer = new Timer();
     Observable.create(subscriber -> {
     timer.onTick(() -> subscriber.onNext("tick"));
     }).subscribe();
     Hot
     

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442. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable response = ws.call();
     

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443. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable response = ws.call();
     response
     .map(str -> str.toLowerCase())
     .subscribe(System.out::println);
     

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444. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable response = ws.call();
     response
     .map(str -> str.toLowerCase())
     .subscribe(System.out::println);
     response
     .subscribe(System.out::println);
     

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445. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable response = ws.call();
     response
     .map(str -> str.toLowerCase())
     .subscribe(System.out::println);
     response
     .subscribe(System.out::println);
     

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446. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable response = ws.call();
     response
     .map(str -> str.toLowerCase())
     .subscribe(System.out::println);
     response
     .subscribe(System.out::println);
     

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447. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable response = ws.call();
     response
     .map(str -> str.toLowerCase())
     .subscribe(System.out::println);
     response
     .subscribe(System.out::println);
     Cold
     

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448. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable response = ws.call();
     response
     .map(str -> str.toLowerCase())
     .subscribe(System.out::println);
     response
     .subscribe(System.out::println);
     Cold
     Création d’un appel
     réseau
     

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449. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable response = ws.call();
     response
     .map(str -> str.toLowerCase())
     .subscribe(System.out::println);
     response
     .subscribe(System.out::println);
     Cold
     Création d’un
     second
     appel réseau
     Création d’un appel
     réseau
     

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450. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Utilisation de MDC pour
     les logs : attention aux
     mauvaises surprises.
     

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451. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     MDC.put("ID", "AAA");
     LOG.warning("first_observable: {}", l);
     

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452. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     WARN AAA [2014-11-10 02:57:24,566] first_observable: 9
     MDC.put("ID", "AAA");
     LOG.warning("first_observable: {}", l);
     

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453. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     WARN AAA [2014-11-10 02:57:24,566] first_observable: 9
     MDC.put("ID", "AAA");
     LOG.warning("first_observable: {}", l);
     Utilisation de ThreadLocal
     

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454. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     WARN AAA [2014-11-10 02:57:24,566] first_observable: 9
     WARN BBB [2014-11-10 02:57:24,576] second_observable: 1
     WARN AAA [2014-11-10 02:57:25,566] first_observable: 10
     WARN CCC [2014-11-10 02:57:25,576] third_observable: 2
     Contexte synchrone
     

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455. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     WARN AAA [2014-11-10 02:57:24,566] first_observable: 9
     WARN BBB [2014-11-10 02:57:24,576] second_observable: 1
     WARN AAA [2014-11-10 02:57:25,566] first_observable: 10
     WARN CCC [2014-11-10 02:57:25,576] third_observable: 2
     Contexte synchrone
     

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456. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     WARN AAA [2014-11-10 02:57:24,566] first_observable: 9
     WARN BBB [2014-11-10 02:57:24,576] third_observable: 1
     WARN AAA [2014-11-10 02:57:25,566] second_observable: 10
     WARN BBB [2014-11-10 02:57:25,576] third_observable: 2
     Contexte asynchrone
     

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457. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     WARN AAA [2014-11-10 02:57:24,566] first_observable: 9
     WARN BBB [2014-11-10 02:57:24,576] third_observable: 1
     WARN AAA [2014-11-10 02:57:25,566] second_observable: 10
     WARN BBB [2014-11-10 02:57:25,576] third_observable: 2
     Contexte asynchrone
     Interleaving
     

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458. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Il est nécessaire de
     remettre en place le
     contexte lors d’un
     changement de
     contexte.
     

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459. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxJavaPlugins.getInstance().registerSchedulersHook(new RxJavaSchedulersHook() {
     @Override
     public Action0 onSchedule(Action0 action) {
     return super.onSchedule(() -> {
     MDC.setContextMap(mdcContextMap);
     try {
     action.call();
     } finally {
     MDC.clear();
     }
     });
     }
     });
     http://blog.mabn.pl/2014/11/rxjava-logback-and-mdc-threadlocal.html
     (version courte)
     

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460. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxJavaPlugins.getInstance().registerSchedulersHook(new RxJavaSchedulersHook() {
     @Override
     public Action0 onSchedule(Action0 action) {
     return super.onSchedule(() -> {
     MDC.setContextMap(mdcContextMap);
     try {
     action.call();
     } finally {
     MDC.clear();
     }
     });
     }
     });
     http://blog.mabn.pl/2014/11/rxjava-logback-and-mdc-threadlocal.html
     (version courte)
     À chaque planification de tâche
     

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461. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxJavaPlugins.getInstance().registerSchedulersHook(new RxJavaSchedulersHook() {
     @Override
     public Action0 onSchedule(Action0 action) {
     return super.onSchedule(() -> {
     MDC.setContextMap(mdcContextMap);
     try {
     action.call();
     } finally {
     MDC.clear();
     }
     });
     }
     });
     http://blog.mabn.pl/2014/11/rxjava-logback-and-mdc-threadlocal.html
     (version courte)
     À chaque planification de tâche
     On planifie une autre tâche
     

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462. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     RxJavaPlugins.getInstance().registerSchedulersHook(new RxJavaSchedulersHook() {
     @Override
     public Action0 onSchedule(Action0 action) {
     return super.onSchedule(() -> {
     MDC.setContextMap(mdcContextMap);
     try {
     action.call();
     } finally {
     MDC.clear();
     }
     });
     }
     });
     http://blog.mabn.pl/2014/11/rxjava-logback-and-mdc-threadlocal.html
     (version courte)
     À chaque planification de tâche
     On planifie une autre tâche
     Qui remet le contexte
     et qui exécute notre tâche
     

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463. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .flatMap(i -> {
     try {
     RandomException.mayThrowException();
     return Observable.empty();
     } catch (IOException e) {
     return Observable.error(e);
     }
     }).subscribe(System.out::println, e -> { /* ... */ });
     

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464. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .flatMap(i -> {
     try {
     RandomException.mayThrowException();
     return Observable.empty();
     } catch (IOException e) {
     return Observable.error(e);
     }
     }).subscribe(System.out::println, e -> { /* ... */ });
     Quelle valeur a généré l’exception ?
     

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465. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .flatMap(i -> {
     try {
     RandomException.mayThrowException();
     return Observable.empty();
     } catch (IOException e) {
     return Observable.error(OnErrorThrowable.addValueAsLastCause(e, i));
     }
     }).subscribe(System.out::println, e -> { /* ... */ });
     Associe l’exception avec une valeur
     

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466. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .flatMap(i -> {
     try {
     RandomException.mayThrowException();
     return Observable.empty();
     } catch (IOException e) {
     return Observable.error(OnErrorThrowable.addValueAsLastCause(e, i));
     }
     }).subscribe(System.out::println, e -> {
     Object value = OnErrorThrowable.from(e).getValue();
     });
     Récupère la valeur depuis l’exception
     

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467. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Grâce à OnErrorThrowable,
     il est possible d'accéder à
     la valeur responsable de
     l’exception
     

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468. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     public interface WebService {
     Observable call();
     }
     Va émettre une valeur ?
     Va émettre plusieurs
     valeurs ?
     Va émettre aucune
     valeur ?
     

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469. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Single = onSuccess | onError
     (Actuellement en @Beta)
     

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470. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Completable = onCompleted | onError
     (Actuellement en @Experimental)
     

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471. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     public interface WebService {
     Observable list();
     Single get();
     Completable perform();
     }
     Va émettre un ensemble de
     valeurs
     va émettre une unique valeur
     ne va pas émettre de valeur
     

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472. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Single et Completable
     permettent d’exprimer
     une intention.
     

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473. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     La souscription permet
     de signaler le
     désabonnement
     à un flux
     

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474. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.interval(1, TimeUnit.SECONDS)
     .subscribe(System.out::println);
     

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475. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Subscription interval = Observable.interval(1, TimeUnit.SECONDS)
     .subscribe(System.out::println);
     Tada !
     

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476. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Subscription interval = Observable.interval(1, TimeUnit.SECONDS)
     .subscribe(System.out::println);
     interval.unsubscribe();
     Stop le flux
     

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477. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     CompositeSubscription
     permet de
     gérer un ensemble
     d’abonnements
     

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478. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Subscription flux1 = Observable.interval(1, TimeUnit.SECONDS)
     .subscribe(System.out::println);
     Subscription flux2 = Observable.interval(100, TimeUnit.MILLISECONDS)
     .subscribe(System.err::println);
     

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479. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Subscription flux1 = Observable.interval(1, TimeUnit.SECONDS)
     .subscribe(System.out::println);
     Subscription flux2 = Observable.interval(100, TimeUnit.MILLISECONDS)
     .subscribe(System.err::println);
     flux1.unsubscribe();
     flux2.unsubscribe();
     

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480. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Subscription flux1 = Observable.interval(1, TimeUnit.SECONDS)
     .subscribe(System.out::println);
     Subscription flux2 = Observable.interval(100, TimeUnit.MILLISECONDS)
     .subscribe(System.err::println);
     CompositeSubscription subscription = new CompositeSubscription();
     subscription.add(flux1);
     subscription.add(flux2); Compose les abonnements
     

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481. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Subscription flux1 = Observable.interval(1, TimeUnit.SECONDS)
     .subscribe(System.out::println);
     Subscription flux2 = Observable.interval(100, TimeUnit.MILLISECONDS)
     .subscribe(System.err::println);
     CompositeSubscription subscription = new CompositeSubscription();
     subscription.add(flux1);
     subscription.add(flux2);
     subscription.unsubscribe(); Désabonne les flux
     

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482. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     private CompositeSubscription subscription;
     @Override
     public void onResume() {
     Subscription interval = Observable.interval(1, TimeUnit.SECONDS)
     .subscribe(/* ... */);
     Subscription click = clicks()
     .subscribe(/*...*/);
     subscription = new CompositeSubscription();
     subscription.add(interval);
     subscription.add(click);
     }
     @Override
     public void onPause() {
     subscription.unsubscribe();
     }
     Désabonne les flux
     

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483. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Du code peut être
     exécuté lors du
     désabonnement
     

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484. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.create(subscriber -> {
     subscriber.add(new Subscription() {
     @Override
     public void unsubscribe() {
     // fermeture du flux
     }
     });
     });
     Fermeture des ressources, etc
     

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485. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.create(subscriber -> {
     subscriber.add(new Subscription() {
     @Override
     public void unsubscribe() {
     // fermeture du flux
     }
     });
     });
     

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486. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Mais comment le faire
     sans utiliser
     Observable.create ?
     

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487. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.using(
     () -> new DB(),
     db -> Observable.just(db.doQuery()),
     db -> db.closeDb())
     .subscribe();
     

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488. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Observable.using(
     () -> new DB(),
     db -> Observable.just(db.doQuery()),
     db -> db.closeDb())
     .subscribe();
     Fermeture des ressources, etc
     

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489. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Avant de se dire au revoir
     

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490. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Les autres talks sur les Reactive Extensions
     - A lite Rx API for the JVM
     Hands On Labs - Mercredi 9h30
     - Baptême du feu avec Rx
     Hands On Labs - Vendredi 11h00
     Alexandre Victoor
     Florent Le Gall
     Sebastien Deleuze
     Stephane Maldini
     

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491. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Remerciements
     Gautier Mechling @Nilhcem
     Simon Baslé @simonbasle
     David Karnok @akarnokd
     Dan Lew @danlew42
     

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492. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Retrouvez nous
     dans les couloirs
     de Devoxx
     

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493. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Y a t’il des points que
     nous n’aurions
     pas abordés ?
     

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494. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     Merci
     

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495. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     

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496. @BriceDutheil @dwursteisen
     #DevoxxFR #Rx
     

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