[Mateusz Herych] Guava beyond Collections

Presentation from GDG DevFest - the biggest Google related event in Ukraine. October 24-25, Lviv. Learn more at http://devfest.gdg.org.ua/

Transcript

2. Java is not perfect.
3. Actually
4. Java sucks.
5. Java sucks. At least compared to other languages.
6. Scala?
7. Scala? case class Person (firstName: String, lastName: String)
9. class Person { private final String firstName; private final String lastName; public Person(String firstName, String lastName) { this.firstName = firstName; this.lastName = lastName; } }
10. class Person { private final String firstName; private final String lastName; public Person(String firstName, String lastName) { this.firstName = firstName; this.lastName = lastName; } public String getFirstName() { return firstName; } public String getLastName() { return lastName; } }
13. Scala? case class Person (firstName: String, lastName: String)
17. Mateusz Herych GDG Kraków Android GDE Engineer, Base CRM
18. Guava
19. Google’s Java
24. null
25. Wikipedia
26. Wikipedia In programming, nullable types are a feature of the type system of some programming languages which allow the value to be set to the special value NULL instead of the usual possible values of the data type. In statically-typed languages, a nullable type is an option type (in functional programming terms), while in dynamically-typed languages (where values have types, but variables do not), equivalent behavior is provided by having a single null value.
29. Null’s inventor
30. Sir Tony Hoare “I call it my billion-dollar mistake. It was the invention of the null reference in 1965.”
31. Billion dollar mistake.
37. Optional
39. Multimaps
41. Key -> List of Values
43. Aygul - [2] Mateusz - [1,2,3]
44. Immutable Collections
45. Mutable state
47. Mutable state
48. Mutable state - Race conditions (multiple threads anyone?)
49. Mutable state - Race conditions (multiple threads anyone?) - Harder debugging (what/who caused THAT change to my object?)
50. Mutable state - Race conditions (multiple threads anyone?) - Harder debugging (what/who caused THAT change to my object?) - Do you trust your libraries?
51. Srsly
52. Do you trust them?
55. Okay, don’t be that paranoid maybe.
56. Usually you can trust your libraries.
57. But!
58. You don’t want to trust your co- workers, don’t you?
59. Immutable = Not changed over time.
61. Also: - ImmutableMap - ImmutableSet - ...
62. Caches
63. Some operations are heavy
64. And we want to avoid invoking them more that it’s needed
65. Caches are hard
66. Caches - Expiration
67. Caches - Expiration - Invalidation
68. Caches - Expiration - Invalidation - Weight/Sizes...
69. Caches - Expiration - Invalidation - Weight/Sizes… - … aaand that’s only beginning!
71. Guava is huge!
72. Preconditions Concurrency I/O EventBus! (but don’t use it on Android) Tons of utilities
73. https://code.google.com/p/guava- libraries/wiki/GuavaExplained
74. Last note.
75. 65K method limit, anyone?
76. Proguard in debug - no obfuscation, just shrinking unused methods
77. Proguard in debug - no obfuscation, just shrinking unused methods. Multidex
78. Proguard in debug - no obfuscation, just shrinking unused methods. Multidex jar stripping?
79. There are WAYS
80. Just give it a try
81. and become a Guava addict
82. ?