Android Fundamentals #5- Networking

Transcript

1. 3as Networking Fundamentals #5 28/11/2017 Britt Barak
2. First,
3. Largest Android Community Android Academy - TLV TLV - Android Academy ~ 2000 members Join Us:
4. Britt Barak @brittBarak • Google developer expert • Android Academy • Women Techmakers
5. Android Academy Staff Yonatan Levin Google Developer Expert & CTO @ KolGene Britt Barak Google Developer Expert Yossi Segev Mobile engineer Colu
6. Mentors program
10. How to perform a network request?
11. How to perform a network request? 1. Ask permission
12. Pleeeeeeaaaase…..?
13. Apps must explicitly request access to resources and data outside their sandbox.
14. AndroidManifest.xml <uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.READ_CONTACTS" /> <uses-permission android:name="android.permission.WRITE_CONTACTS" /> <uses-permission android:name="android.permission.CAMERA" /> <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
15. Normal Granted by OS Permission Types Click for documentation Dangerous Granted by user Click for documentation
16. API 22- : Upon Install
17. developer.android.com/training/permissions/requesting.html API 23+ : Runtime
18. developer.android.com/training/permissions/requesting.html API 23+ : Runtime
19. Questions?
21. Client Server Request Response
22. • Hypertext Transfer Protocol. • Stateless protocol. • By default: HTTP uses port 80 and HTTPS uses port 443 HTTP
23. Request Verb + URL (+ Payload)
24. HTTP Verb • GET: fetch an existing resource, by the URL’s info. • POST: create a new resource, by the request’s payload. • PUT: update an existing resource, by the request’s payload. • DELETE: delete an existing resource.
25. URL (Universal Resource Locator) http://www.domain.com:1234/ path/to/resource ?language=english&place=tlv protocol host port path Query parameters
26. Response Status Code + Payload (body)
27. Status Code 1xx: Informational Messages - Expect: 100-continue 2xx: Successful - 200 OK, 204 No Content 3xx: Redirection - Additional action needed. Commonly go to another url. 4xx: Client Error - 404 Not Found, 400 Bad Request,401 Unauthorized, 5xx: Server Error - 503 Service Unavailable
28. Overlook
29. URL url = new URL(myurl); HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection(); urlConnection.setReadTimeout(10000 /* milliseconds */); urlConnection.setConnectTimeout(15000 /* milliseconds */); urlConnection.setRequestMethod("GET"); urlConnection.setDoInput(true); // Starts the query urlConnection.connect(); int response = urlConnection.getResponseCode(); is = urlConnection.getInputStream(); // Convert the InputStream into a string String contentAsString = readIt(is, len); return contentAsString;
30. UI Thread #1 Rule Never block it
31. NetworkOnMainThreadException
32. OMG!
33. Luckily, we have
34. Luckily, we have square.github.io
35. Retrofit http://square.github.io/retrofit/ https://futurestud.io/blog/retrofit-getting-started-and-android-client
36. build.gradle() dependencies { //... implementation 'com.squareup.retrofit2:retrofit:2.3.0' }
37. Server Json Android App Java Retrofit
38. Request Verb + URL (+ Payload)
41. https://api.foursquare.com/v2/ venues/explore Base url / Host Path / Endpoint ll Query
42. static final String BASE_URL = "https://api.foursquare.com/v2/"; ServiceGenerator.java
43. @GET("venues/explore") Call<VenuesResponse> getVenues(); public interface FoursquareService ?
44. @GET("venues/explore") Call<VenuesResponse> getVenues(@Query("ll") String location); public interface FoursquareService
45. @GET("venues/explore") Call<VenuesResponse> getVenues( @QueryMap Map<String, String> options); @GET("venues/{VENUE_ID}/photos") Call<PhotosResponse> getPhotos( @Path("VENUE_ID") String venueId); //an example I made up :) @POST("venues/add") Call<AddVenueResponse> addVenue( @Header("Authorization") String authorization, @Body("name") Venue venue);
46. Questions?
47. Response Status Code + Payload (body)
48. What language does the server speak?
49. "groups": [ { "type": "Recommended Places", "name": "recommended", "items": [ { "reasons": { "count": 0, "items": [ { "summary": "This spot is popular", "type": "general", "reasonName": "globalInteractionReason" } ] }, "venue": {
50. • Advanced REST Client • Postman • Swagger • ….
51. Server Json Android App Java Serialization De-Serialization
52. Server Json Android App Java Gson github.com/google/gson
53. Creating the data model (POJO)
54. "venue": { "id":"56d92e05498e6c54b6325b19", "name": "Zepra", "contact": { "phone": "036240044", "formattedPhone":"03-624-0044" "rating": 9.5, "hours": {...} , "photoUrl": "........" }
55. class Venue { } "venue": { "id":"56d92e05498e6c54b6325b19", "name": "Zepra", "contact": { "phone": "036240044", "formattedPhone":"03-624-0044" } "rating": 9.5, "hours": {...} , "photoUrl": "........" }
56. class Venue { String id; } "venue": { "id":"56d92e05498e6c54b6325b19", "name": "Zepra", "contact": { "phone": "036240044", "formattedPhone":"03-624-0044" } "rating": 9.5, "hours": {...} , "photoUrl": "........" }
57. class Venue { String id; String name; } "venue": { "id":"56d92e05498e6c54b6325b19", "name": "Zepra", "contact": { "phone": "036240044", "formattedPhone":"03-624-0044" } "rating": 9.5, "hours": {...} , "photoUrl": "........" }
58. class Venue { String id; String name; ContactInfo contact; } class ContactInfo { String phone; String formattedPhone; } "venue": { "id":"56d92e05498e6c54b6325b19", "name": "Zepra", "contact": { "phone": "036240044", "formattedPhone":"03-624-0044" } "rating": 9.5, "hours": {...} , "photoUrl": "........" }
59. class Venue { String id; String name; @SerializedName("contact") ContactInfo contactInfo; } class ContactInfo { String phone; String formattedPhone; } "venue": { "id":"56d92e05498e6c54b6325b19", "name": "Zepra", "contact": { "phone": "036240044", "formattedPhone":"03-624-0044" } "rating": 9.5, "hours": {...} , "photoUrl": "........" }
60. class Venue { String id; String name; @SerializedName("contact") ContactInfo contactInfo; } class ContactInfo { String phone; String formattedPhone; } "venue": { "id":"56d92e05498e6c54b6325b19", "name": "Zepra", "contact": { "phone": "036240044", "formattedPhone":"03-624-0044" } "rating": 9.5, "hours": {...} , "photoUrl": "........" }
61. class Venue { String id; String name; @SerializedName("contact") ContactInfo contactInfo; float rating; } class ContactInfo { String phone; String formattedPhone; } "venue": { "id":"56d92e05498e6c54b6325b19", "name": "Zepra", "contact": { "phone": "036240044", "formattedPhone":"03-624-0044" } "rating": 9.5, "hours": {...} , "photoUrl": "........" }
62. class Venue { String id; String name; @SerializedName("contact") ContactInfo contactInfo; float rating; } class ContactInfo { String phone; String formattedPhone; } "venue": { "id":"56d92e05498e6c54b6325b19", "name": "Zepra", "contact": { "phone": "036240044", "formattedPhone":"03-624-0044" } "rating": 9.5, "hours": {...} , "photoUrl": "........" }
63. class Venue { String id; String name; @SerializedName("contact") ContactInfo contactInfo; String photoUrl; } class ContactInfo { String phone; String formattedPhone; } "venue": { "id":"56d92e05498e6c54b6325b19", "name": "Zepra", "contact": { "phone": "036240044", "formattedPhone":"03-624-0044" } "rating": 9.5, "hours": {...} , "photoUrl": "........" }
64. Questions?
65. {"items":[{"reasons":{"count":0,"items":[{"summary":"This spot is popular","type":"general","reasonName":"globalInteractionReason"}]},"venue":{"id ":"4b488bfff964a520184f26e3","name":"Anita La Mamma Del Gelato (הטינא)","contact":{"phone":"+97235170505","formattedPhone":"+972 3-517-0505"},"location":{"address":"42 Shabazi St","crossStreet":"at Pines St","lat":32.06274494279335,"lng":34.76648985707776,"labeledLatLngs":[{"label":" display","lat":32.06274494279335,"lng":34.76648985707776}],"postalCode":"65150", "cc":"IL","city":"ופי-ביבא לת","state":"ביבא לת","country":" לארשי","formattedAddress":["42 Shabazi St (at Pines St)","","65150 ופי-ביבא לת לארשי"]},"categories":[{"id":"4bf58dd8d48988d1c9941735","name":"Ice Cream Shop","pluralName":"Ice Cream Shops","shortName":"Ice Cream","icon":{"prefix":"https://ss3.4sqi.net/img/categories_v2/food/icecream_", "suffix":".png"},"primary":true}],"verified":false,"stats":{"checkinsCount":1941 ,"usersCount":1192,"tipCount":78},"url":"http://www.anitaglida.co.il","price":{" tier":1,"message":"Cheap","currency":"$"},"rating":9.5,"ratingColor":"00B551","r atingSignals":310,"allowMenuUrlEdit":true,"beenHere":{"count":0,"marked":false," lastCheckinExpiredAt":0},"hours":{"status":"Open until 12:30 AM","richStatus":{"entities":[],"text":"Open until 12:30
67. class VenuesResponse { List<Group> groups; class Group { List<Item> items; } class Item { Venue venue; } }
68. Gson gson = new Gson(); venuePojo = gson.fromJson(venueJson, Venue.class); venueJson = gson.toJson(venuePojo);
69. Server Json Android App Java Retrofit GSON Converter
70. Convertors • Gson: com.squareup.retrofit2:converter-gson • Jackson: com.squareup.retrofit2:converter-jackson • Moshi: com.squareup.retrofit2:converter-moshi • Protobuf: com.squareup.retrofit2:converter-protobuf • Wire: com.squareup.retrofit2:converter-wire • Simple XML: com.squareup.retrofit2:converter-simplexml • Scalars: com.squareup.retrofit2:converter-scalars
71. Make the request already!!
72. How to perform a network request? 1. Ask permission
73. How to perform a network request? 1. Ask permission 2. Setup the Service Generator
74. static final String BASE_URL = "https://api.foursquare.com/v2/"; ServiceGenerator.java
75. static final String BASE_URL = "https://api.foursquare.com/v2/"; static Retrofit.Builder retrofitBuilder = new Retrofit.Builder() ServiceGenerator.java
76. static final String BASE_URL = "https://api.foursquare.com/v2/"; static Retrofit.Builder retrofitBuilder = new Retrofit.Builder() .baseUrl(BASE_URL) ServiceGenerator.java
77. static final String BASE_URL = "https://api.foursquare.com/v2/"; static Retrofit.Builder retrofitBuilder = new Retrofit.Builder() .baseUrl(BASE_URL) .addConverterFactory(GsonConverterFactory.create()); ServiceGenerator.java
78. Http Client OKHttp square.github.io/okhttp
79. static OkHttpClient.Builder httpClient = new OkHttpClient.Builder(); ServiceGenerator.java
80. static OkHttpClient.Builder httpClient = new OkHttpClient.Builder(); static Retrofit retrofit = retrofitBuilder .client(httpClient.build()) .build(); ServiceGenerator.java
81. Question: why are ServiceGenerator fields are static?
82. How to perform a network request? 1. Ask permission 2. Setup the Service Generator 3. Create the response data model
83. class VenuesResponse { List<Group> groups; class Group { List<Item> items; } class Item { Venue venue; } } Rem inder
84. How to perform a network request? 1. Ask permission 2. Setup the Service Generator 3. Create the response data model 4. Create the service interface
85. @GET("venues/explore") Call<VenuesResponse> getVenues(@Query("ll") String location); public interface FoursquareService Rem inder
86. How to perform a network request? 1. Ask permission 2. Setup the Service Generator 3. Create the response data model 4. Create the service interface 5. Perform Call!
87. FoursquareService foursquareService = ServiceGenerator.retrofit .create(FoursquareService.class);
88. FoursquareService foursquareService = ServiceGenerator.createService(FoursquareService.class); Call<VenuesResponse> call = foursquareService.getVenues(location);
89. call.enqueue(callback); Asynchronous
90. callback = new Callback<VenuesResponse>() { };
91. callback = new Callback<VenuesResponse>() { @Override public void onResponse(Call<VenuesResponse> call, Response<VenuesResponse> response) { VenuesResponse data = response.body(); adapter.setItems(data); } };
92. callback = new Callback<VenuesResponse>() { @Override public void onResponse(Call<VenuesResponse> call, Response<VenuesResponse> response) { VenuesResponse data = response.body(); //handle response data } @Override public void onFailure(...) { //handle failure } };
93. VenuesResponse venuesResponse = call.execute().body(); Synchronous
94. VenuesAdapter.java - (Example) public void onBindViewHolder(VenueViewHolder holder, int position) { textView.setText( venues.get(position).getName()); }
96. Questions?
97. Load images!
98. Challenges 1. Heavy 2. Out of memory (Exception) 3. Caching 4. Resize 5. Image manipulation (round corners…)
99. Picasso http://square.github.io/picasso/
100. Server Json Android App Java Picasso OkHttp
101. build.gradle() dependencies { //... implementation 'com.squareup.picasso:picasso:2.5.2' }
102. Picasso .with(context) .load(url) .into(view);
103. VenuesAdapter.java - (Example) public void onBindViewHolder(VenueViewHolder holder, int position){ textView.setText(venues.get(position).getName()); }
104. VenuesAdapter.java - (Example) public void onBindViewHolder(VenueViewHolder holder, int position){ textView.setText(venues.get(position).getName()); if (! TextUtils.isEmpty(venue.getImageUrl())) { } }
105. VenuesAdapter.java - (Example) public void onBindViewHolder(VenueViewHolder holder, int position){ textView.setText(venues.get(position).getName()); if (! TextUtils.isEmpty(venue.getImageUrl())) { Picasso.with(imageView.getContext()) .load(venue.getImageUrl()) .into(imageView); } }
107. We did it!!!
108. Network Profiler
110. Network Traffic Tool https://developer.android.com/studio/profile/ddms.html
111. Facebook Stetho https://code.facebook.com/posts/393927910787513/stetho-a-new-debugging-platform-for-android/
113. Interceptors [Bonus]
115. static HttpLoggingInterceptor logging = new HttpLoggingInterceptor() .setLevel(HttpLoggingInterceptor.Level.BODY); httpClient.addInterceptor(logging) .addNetworkInterceptor(logging) //... ServiceGenerator.java
116. Interceptor apiKeyInterceptor = new Interceptor() { @Override public Response intercept(Chain chain) throws IOException { } ServiceGenerator.java
117. Interceptor apiKeyInterceptor = new Interceptor() { @Override public Response intercept(Chain chain) throws IOException { Request original = chain.request(); HttpUrl originalHttpUrl = original.url(); } ServiceGenerator.java
118. Interceptor apiKeyInterceptor = new Interceptor() { @Override public Response intercept(Chain chain) throws IOException { Request original = chain.request(); HttpUrl originalHttpUrl = original.url(); HttpUrl url = originalHttpUrl.newBuilder() .addQueryParameter("client_id",CLIENT_ID) .addQueryParameter("client_secret",CLIENT_SECRET) .build(); ServiceGenerator.java
119. ... Request.Builder requestBuilder = original.newBuilder().url(url); return chain.proceed(requestBuilder.build()); } ServiceGenerator.java
120. httpClient.addInterceptor(logging) .addInterceptor(apiKeyInterceptor) //... ServiceGenerator.java
121. Questions?
122. Source code for the demo [read the ReadMe first :) ] https://goo.gl/WfnSpd
123. Thank you
124. Exercise goo.gl/BGPzkt