Simple HTTP with Retrofit 2 (Droidcon NYC 2015)

Transcript

1. Retrofit Two Jake Wharton

2. Retrofit 2 will be out by the end of this

   year " " — Naïve Man

3. Retrofit 2 will be out by the end of this

   year " " — Jake Wharton

4. Retrofit 2 will be out by the end of this

   year " " Droidcon NYC 2014 — Jake Wharton

5. Retrofit 2 will be out by the end of this

   year " " Droidcon NYC 2015 — Jake Wharton

6. Retrofit 1

7. Retrofit 1 • Made open source on October 13th, 2010

8. Retrofit 1 • Made open source on October 13th, 2010

   • Originally a Bob Lee joint

9. Retrofit 1 • Made open source on October 13th, 2010

   • Originally a Bob Lee joint • Took over / stole stewardship mid-2012

10. Retrofit 1 • Made open source on October 13th, 2010

    • Originally a Bob Lee joint • Took over / stole stewardship mid-2012 • Released 1.0 on May 13th, 2013

11. Retrofit 1 • Made open source on October 13th, 2010

    • Originally a Bob Lee joint • Took over / stole stewardship mid-2012 • Released 1.0 on May 13th, 2013 • 18 releases post-1.0 with tons of features / fixes

12. The Good

13. The Good • Interface service declarations • Method and parameter

    annotations customize request

14. Interface and annotations interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 List<Contributor> repoContributors(
 @Path("owner")

    String owner,
 @Path("repo") String repo);
 }

15. The Good • Interface service declarations • Method and parameter

    annotations customize request • Pluggable HTTP client and serialization

16. Pluggable client and serialization builder.setClient(new UrlConnectionClient()); builder.setClient(new ApacheClient()); builder.setClient(new OkClient());

17. Pluggable client and serialization builder.setClient(new UrlConnectionClient()); builder.setClient(new ApacheClient()); builder.setClient(new OkClient());

    builder.setClient(new CustomClient());

18. Pluggable client and serialization interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 List<Contributor> repoContributors(


    @Path("owner") String owner,
 @Path("repo") String repo);
 }

19. Pluggable client and serialization interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 List<Contributor> repoContributors(


    @Path("owner") String owner,
 @Path("repo") String repo);
 } builder.setConverter(new GsonConverter()); builder.setConverter(new JacksonConverter());

20. Pluggable client and serialization interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 ContributorResponse repoContributors(


    @Path("owner") String owner,
 @Path("repo") String repo);
 }

21. Pluggable client and serialization interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 ContributorResponse repoContributors(


    @Path("owner") String owner,
 @Path("repo") String repo);
 } builder.setConverter(new ProtoConverter()); builder.setConverter(new WireConverter());

22. Pluggable client and serialization interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 ContributorResponse repoContributors(


    @Path("owner") String owner,
 @Path("repo") String repo);
 } builder.setConverter(new ProtoConverter()); builder.setConverter(new WireConverter()); builder.setConverter(new SimpleXMLConverter());

23. Pluggable client and serialization interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 ContributorResponse repoContributors(


    @Path("owner") String owner,
 @Path("repo") String repo);
 } builder.setConverter(new ProtoConverter()); builder.setConverter(new WireConverter()); builder.setConverter(new SimpleXMLConverter()); builder.setConverter(new CustomConverter());

24. The Good • Interface service declarations • Method and parameter

    annotations customize request • Pluggable HTTP client and serialization • Synchronous, asynchronous, and RxJava execution

25. Sync, async, and RxJava interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 List<Contributor> repoContributors(


    @Path("owner") String owner,
 @Path("repo") String repo);
 } List<Contributor> contributors = gitHubService.repoContributors("square", "retrofit");

26. Sync, async, and RxJava interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 void repoContributors(


    @Path("owner") String owner,
 @Path("repo") String repo,
 Callback<List<Contributor>> cb);
 } service.repoContributors("square", "retrofit", new Callback<List<Contributor>>() {
 @Override void success(List<Contributor> contributors, Response response) {
 // ...
 }
 
 @Override void failure(RetrofitError error) {
 // ...
 }
 });

27. Sync, async, and RxJava interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Observable<List<Contributor>> repoContributors(


    @Path("owner") String owner,
 @Path("repo") String repo);
 } gitHubService.repoContributors("square", "retrofit")
 .subscribe(new Action1<List<Contributor>>() {
 @Override public void call(List<Contributor> contributors) {
 // ...
 }
 });

28. The Good • Interface service declarations • Method and parameter

    annotations customize request • Pluggable HTTP client and serialization • Synchronous, asynchronous, and RxJava execution

29. The Not-So-Good

30. The Not-So-Good • Request/Response (and friends) model classes

31. Request/Response model classes

32. The Not-So-Good • Request/Response (and friends) model classes • No

    access to serialized body and response data

33. No access to body and response interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")


    List<Contributor> repoContributors(
 @Path("owner") String owner,
 @Path("repo") String repo);
 }X

34. No access to body and response interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")


    List<Contributor> repoContributors(
 @Path("owner") String owner,
 @Path("repo") String repo);
 @GET("/repos/{owner}/{repo}/contributors")
 Response repoContributors2(
 @Path("owner") String owner,
 @Path("repo") String repo);
 }X

35. The Not-So-Good • Request/Response (and friends) model classes • No

    access to serialized body and response data • Rigid execution mechanisms

36. Rigid execution mechanisms interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 List<Contributor> repoContributors(
 @Path("owner")

    String owner,
 @Path("repo") String repo); @GET("/repos/{owner}/{repo}/contributors")
 void repoContributors(
 @Path("owner") String owner,
 @Path("repo") String repo,
 Callback<List<Contributor>> cb);
 }

37. Rigid execution mechanisms interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Observable<List<Contributor>> repoContributors(
 @Path("owner")

    String owner,
 @Path("repo") String repo);
 }

38. Rigid execution mechanisms interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 ListenableFuture<List<Contributor>> repoContributors(
 @Path("owner")

    String owner,
 @Path("repo") String repo);
 }

39. Rigid execution mechanisms interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 CompletableFuture<List<Contributor>> repoContributors(
 @Path("owner")

    String owner,
 @Path("repo") String repo);
 }

40. The Not-So-Good • Request/Response (and friends) model classes • No

    access to serialized body and response data • Rigid execution mechanisms • Inefficient converter usage

41. Inefficient converter usage interface Converter {
 Object fromBody(TypedInput body, Type

    type);
 TypedOutput toBody(Object object);
 }

42. Inefficient converter usage interface Converter {
 Object fromBody(TypedInput body, Type

    type);
 TypedOutput toBody(Object object);
 } Type TypeAdapter TypedInput/Output JsonAdapter ObjectReader/Writer Parser ProtoAdapter

43. Inefficient converter usage interface Converter {
 Object fromBody(TypedInput body, Type

    type);
 TypedOutput toBody(Object object);
 } Type TypeAdapter TypedInput/Output JsonAdapter ObjectReader/Writer Parser ProtoAdapter

44. The Not-So-Good • Request/Response (and friends) model classes • No

    access to serialized body and response data • Rigid execution mechanisms • Inefficient converter usage • Simple custom parameter types support

45. Simple custom parameter types interface GitHubService {
 @GET("/search/repositories")
 RepositoriesResponse searchRepos(


    @Query("q") String query,
 @Query("since") Date since);
 }X

46. Simple custom parameter types interface GitHubService {
 @GET("/search/repositories")
 RepositoriesResponse searchRepos(


    @Query("q") String query,
 @Query("since") Date since);
 }X /search/repositories?q=retrofit&since=2015-08-27

47. Simple custom parameter types interface GitHubService {
 @GET("/search/repositories")
 RepositoriesResponse searchRepos(


    @Query("q") String query,
 @Query("since") Date since);
 }X /search/repositories?q=retrofit&since=2015-08-27 /search/repositories?q=retrofit&since=20150827

48. The Not-So-Good • Request/Response (and friends) model classes • No

    access to serialized body and response data • Rigid execution mechanisms • Inefficient converter usage • Simple custom parameter types support

49. Retrofit 2

50. Retrofit 2 • Call encapsulates single request/response interaction

51. Call • Models a single request/response pair

52. Call • Models a single request/response pair • Separates request

    creation from response handling

53. Call • Models a single request/response pair • Separates request

    creation from response handling • Each instance can only be used once...

54. Call • Models a single request/response pair • Separates request

    creation from response handling • Each instance can only be used once... • ...instances can be cloned

55. Call • Models a single request/response pair • Separates request

    creation from response handling • Each instance can only be used once... • ...instances can be cloned • Supports both synchronous and asynchronous execution.

56. Call • Models a single request/response pair • Separates request

    creation from response handling • Each instance can only be used once... • ...instances can be cloned • Supports both synchronous and asynchronous execution. • Can be (actually) canceled

57. Call interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 List<Contributor> repoContributors(
 @Path("owner") String owner,


    @Path("repo") String repo); }X

58. Call interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String owner,


    @Path("repo") String repo);
 }X

59. Call interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String owner,


    @Path("repo") String repo);
 }

60. Call interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String owner,


    @Path("repo") String repo);
 } Call<List<Contributor>> call = gitHubService.repoContributors("square", "retrofit");

61. Call Call<List<Contributor>> call = gitHubService.repoContributors("square", "retrofit");

62. Call Call<List<Contributor>> call = gitHubService.repoContributors("square", "retrofit"); 
 response = call.execute();

63. Call Call<List<Contributor>> call = gitHubService.repoContributors("square", "retrofit"); 
 response = call.execute();

    // This will throw IllegalStateException:
 response = call.execute();

64. Call Call<List<Contributor>> call = gitHubService.repoContributors("square", "retrofit"); 
 response = call.execute();

    // This will throw IllegalStateException:
 response = call.execute(); Call<List<Contributor>> call2 = call.clone();
 // This will not throw:
 response = call2.execute();

65. Call Call<List<Contributor>> call = gitHubService.repoContributors("square", "retrofit");

66. Call Call<List<Contributor>> call = gitHubService.repoContributors("square", "retrofit"); 
 call.enqueue(new Callback<List<Contributor>>() {


    @Override void onResponse(/* ... */) {
 // ...
 }
 
 @Override void onFailure(Throwable t) {
 // ...
 }
 });

67. Call Call<List<Contributor>> call = gitHubService.repoContributors("square", "retrofit"); call.enqueue( ); // or...

    call.execute();

68. Call Call<List<Contributor>> call = gitHubService.repoContributors("square", "retrofit"); call.enqueue( ); // or...

    call.execute(); // later... call.cancel();

69. Retrofit 2 • Call encapsulates single request/response interaction • Parameterized

    Response object

70. Response Call<List<Contributor>> call = gitHubService.repoContributors("square", "retrofit"); response = call.execute();

71. Response Call<List<Contributor>> call = gitHubService.repoContributors("square", "retrofit"); Response<List<Contributor>> response = call.execute();

72. Response Call<List<Contributor>> call = gitHubService.repoContributors("square", "retrofit"); Response<List<Contributor>> response = call.execute();

73. Response Call<List<Contributor>> call = gitHubService.repoContributors("square", "retrofit"); call.enqueue(new Callback<List<Contributor>>() {
 @Override

    void onResponse(/* ... */) {
 // ...
 }X
 
 @Override void failure(Throwable t) {
 // ...
 }X
 });

74. Response Call<List<Contributor>> call = gitHubService.repoContributors("square", "retrofit"); call.enqueue(new Callback<List<Contributor>>() {
 @Override

    void onResponse(Response<List<Contributor>> response) {
 // ...
 }X
 
 @Override void failure(Throwable t) {
 // ...
 }X
 });

75. Response Call<List<Contributor>> call = gitHubService.repoContributors("square", "retrofit"); call.enqueue(new Callback<List<Contributor>>() {
 @Override

    void onResponse(Response<List<Contributor>> response) {
 // ...
 }
 
 @Override void failure(Throwable t) {
 // ...
 }
 });

76. Response class Response<T> {
 }X

77. Response class Response<T> {
 int code();
 String message(); Headers headers();


    }X

78. Response class Response<T> {
 int code();
 String message(); Headers headers();


    
 boolean isSuccess();
 }X

79. Response class Response<T> {
 int code();
 String message(); Headers headers();


    
 boolean isSuccess(); T body();
 ResponseBody errorBody();
 }X

80. Response class Response<T> {
 int code();
 String message(); Headers headers();


    
 boolean isSuccess(); T body();
 ResponseBody errorBody(); com.squareup.okhttp.Response raw();
 }X

81. Retrofit 2 • Call encapsulates single request/response interaction • Parameterized

    Response object

82. If it isn't broken...

83. Fixed Query Param interface SomeService {
 @GET("/some/endpoint?fixed=query")
 Call<SomeResponse> someEndpoint();
 }

    someService.someEndpoint(); // GET /some/endpoint?fixed=query HTTP/1.1

84. Dynamic Query Param interface SomeService {
 @GET("/some/endpoint")
 Call<SomeResponse> someEndpoint(
 @Query("dynamic")

    String dynamic);
 } someService.someEndpoint("query"); // GET /some/endpoint?dynamic=query HTTP/1.1

85. Dynamic Query Param Map interface SomeService {
 @GET("/some/endpoint")
 Call<SomeResponse> someEndpoint(


    @QueryMap Map<String, String> dynamic);
 } someService.someEndpoint( Collections.singletonMap("dynamic", "query")); // GET /some/endpoint?dynamic=query HTTP/1.1

86. Omit Dynamic Query Param interface SomeService {
 @GET("/some/endpoint")
 Call<SomeResponse> someEndpoint(


    @Query("dynamic") String dynamic);
 } someService.someEndpoint(null); // GET /some/endpoint HTTP/1.1

87. Fixed+Dynamic Query Params interface SomeService {
 @GET("/some/endpoint?fixed=query")
 Call<SomeResponse> someEndpoint(
 @Query("dynamic")

    String dynamic);
 } someService.someEndpoint("query"); // GET /some/endpoint?fixed=query&dynamic=query HTTP/1.1

88. Path Replacement interface SomeService {
 @GET("/some/endpoint/{foo}")
 Call<SomeResponse> someEndpoint(
 @Path("thing") String

    thing);
 } someService.someEndpoint("bar"); // GET /some/endpoint/bar HTTP/1.1

89. Fixed Header interface SomeService {
 @GET("/some/endpoint") @Headers("Accept-Encoding: application/json")
 Call<SomeResponse> someEndpoint();


    } someService.someEndpoint(); // GET /some/endpoint HTTP/1.1 // Accept-Encoding: application/json

90. Dynamic Header interface SomeService {
 @GET("/some/endpoint")
 Call<SomeResponse> someEndpoint( @Header("Location") String

    location);
 } someService.someEndpoint("Droidcon NYC 2015"); // GET /some/endpoint HTTP/1.1 // Location: Droidcon NYC 2015

91. Omit Dynamic Header interface SomeService {
 @GET("/some/endpoint")
 Call<SomeResponse> someEndpoint( @Header("Location")

    String location);
 } someService.someEndpoint(null); // GET /some/endpoint HTTP/1.1

92. Fixed+Dynamic Header interface SomeService {
 @GET("/some/endpoint") @Headers("Accept-Encoding: application/json")
 Call<SomeResponse> someEndpoint(

    @Header("Location") String location);
 } someService.someEndpoint("Droidcon NYC 2015"); // GET /some/endpoint HTTP/1.1 // Accept-Encoding: application/json // Location: Droidcon NYC 2015

93. Post Without Body interface SomeService {
 @POST("/some/endpoint")
 Call<SomeResponse> someEndpoint();
 }

    someService.someEndpoint(); // POST /some/endpoint?fixed=query HTTP/1.1 // Content-Length: 0

94. Post With Body interface SomeService {
 @POST("/some/endpoint")
 Call<SomeResponse> someEndpoint( @Body

    SomeRequest body);
 } someService.someEndpoint(); // POST /some/endpoint HTTP/1.1 // Content-Length: 3 // Content-Type: greeting // // Hi!

95. Form Encoded Fields interface SomeService {
 @FormUrlEncoded @POST("/some/endpoint")
 Call<SomeResponse> someEndpoint(

    @Field("name1") String name1, @Field("name2") String name2);
 } someService.someEndpoint("value1", "value2"); // POST /some/endpoint HTTP/1.1 // Content-Length: 25 // Content-Type: application/x-www-form-urlencoded // // name1=value1&name2=value2

96. Omit Form Encoded Field interface SomeService {
 @FormUrlEncoded @POST("/some/endpoint")
 Call<SomeResponse>

    someEndpoint( @Field("name1") String name1, @Field("name2") String name2);
 } someService.someEndpoint("value1", null); // POST /some/endpoint HTTP/1.1 // Content-Length: 12 // Content-Type: application/x-www-form-urlencoded // // name1=value1

97. Form Encoded Field Map interface SomeService {
 @FormUrlEncoded @POST("/some/endpoint")
 Call<SomeResponse>

    someEndpoint( @FieldMap Map<String, String> names);
 } someService.someEndpoint( ImmutableMap.of("name1", "value1", "name2", "value2")); // POST /some/endpoint HTTP/1.1 // Content-Length: 25 // Content-Type: application/x-www-form-urlencoded // // name1=value1&name2=value2

98. Multipart Parts interface SomeService {
 @Multipart @POST("/some/endpoint")
 Call<SomeResponse> someEndpoint( @Part("name1")

    String name1, @Part("name2") String name2);
 } someService.someEndpoint("value1", "value2"); // POST /some/endpoint HTTP/1.1 // Content-Length: 102 // Content-Type: application/form-data // // ...

99. Omit Multipart Part interface SomeService {
 @Multipart @POST("/some/endpoint")
 Call<SomeResponse> someEndpoint(

    @Part("name1") String name1, @Part("name2") String name2);
 } someService.someEndpoint("value1", null); // POST /some/endpoint HTTP/1.1 // Content-Length: 56 // Content-Type: application/form-data // // ...

100. Multipart Part Map interface SomeService {
 @Multipart @POST("/some/endpoint")
 Call<SomeResponse> someEndpoint(

     @PartMap Map<String, String> names);
 } someService.someEndpoint( ImmutableMap.of("name1", "value1", "name2", "value2")); // POST /some/endpoint HTTP/1.1 // Content-Length: 102 // Content-Type: application/form-data // // ...

101. If it isn't broken...

102. Retrofit 2 • Call encapsulates single request/response interaction • Parameterized

     Response object • Dynamic URL parameter

103. Dynamic URL interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String

     owner,
 @Path("repo") String repo);
 }

104. Dynamic URL interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String

     owner,
 @Path("repo") String repo);
 } Call<List<Contributor>> call = gitHubService.repoContributors("square", "retrofit"); Response<List<Contributor>> response = call.execute();

105. Dynamic URL interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String

     owner,
 @Path("repo") String repo);
 } Call<List<Contributor>> call = gitHubService.repoContributors("square", "retrofit"); Response<List<Contributor>> response = call.execute(); // HTTP/1.1 200 OK // Link: <https://api.github.com/repositories/892275/contributors? page=2>; rel="next", <https://api.github.com/repositories/892275/ contributors?page=3>; rel="last" // ...

106. Dynamic URL Response<List<Contributor>> response = call.execute(); // HTTP/1.1 200 OK

     // Link: <https://api.github.com/repositories/892275/contributors? page=2>; rel="next", <https://api.github.com/repositories/892275/ contributors?page=3>; rel="last" // ...

107. Dynamic URL Response<List<Contributor>> response = call.execute(); // HTTP/1.1 200 OK

     // Link: <https://api.github.com/repositories/892275/contributors? page=2>; rel="next", <https://api.github.com/repositories/892275/ contributors?page=3>; rel="last" // ... String links = response.headers().get("Link");

108. Dynamic URL Response<List<Contributor>> response = call.execute(); // HTTP/1.1 200 OK

     // Link: <https://api.github.com/repositories/892275/contributors? page=2>; rel="next", <https://api.github.com/repositories/892275/ contributors?page=3>; rel="last" // ... String links = response.headers().get("Link"); String nextLink = nextFromGitHubLinks(links);

109. Dynamic URL Response<List<Contributor>> response = call.execute(); // HTTP/1.1 200 OK

     // Link: <https://api.github.com/repositories/892275/contributors? page=2>; rel="next", <https://api.github.com/repositories/892275/ contributors?page=3>; rel="last" // ... String links = response.headers().get("Link"); String nextLink = nextFromGitHubLinks(links); // https://api.github.com/repositories/892275/contributors?page=2

110. Dynamic URL interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String

     owner,
 @Path("repo") String repo);
 }X

111. Dynamic URL interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String

     owner,
 @Path("repo") String repo); 
 @GET
 Call<List<Contributor>> repoContributorsPaginate(
 @Url String url);
 }X

112. Dynamic URL String nextLink = nextFromGitHubLinks(links); // https://api.github.com/repositories/892275/contributors?page=2

113. Dynamic URL String nextLink = nextFromGitHubLinks(links); // https://api.github.com/repositories/892275/contributors?page=2 Call<List<Contributor>> nextCall

     = gitHubService.repoContributorsPaginate(nextLink);

114. Retrofit 2 • Call encapsulates single request/response interaction • Parameterized

     Response object • Dynamic URL parameter • Multiple, efficient converters

115. Converters interface SomeProtoService {
 @GET("/some/proto/endpoint")
 Call<SomeProtoResponse> someProtoEndpoint(); }X interface SomeJsonService

     {
 @GET("/some/json/endpoint")
 Call<SomeJsonResponse> someJsonEndpoint();
 }X

116. Converters interface SomeService {
 @GET("/some/proto/endpoint")
 Call<SomeProtoResponse> someProtoEndpoint(); 
 @GET("/some/json/endpoint")
 Call<SomeJsonResponse>

     someJsonEndpoint();
 }X 
 
 SomeProtoResponse

117. Converters interface SomeService {
 @GET("/some/proto/endpoint")
 Call<SomeProtoResponse> someProtoEndpoint(); 
 @GET("/some/json/endpoint")
 Call<SomeJsonResponse>

     someJsonEndpoint();
 }X SomeProtoResponse

118. Converters interface SomeService {
 @GET("/some/proto/endpoint")
 Call<SomeProtoResponse> someProtoEndpoint(); 
 @GET("/some/json/endpoint")
 Call<SomeJsonResponse>

     someJsonEndpoint();
 }X SomeProtoResponse Proto? Yes!

119. Converters interface SomeService {
 @GET("/some/proto/endpoint")
 Call<SomeProtoResponse> someProtoEndpoint(); 
 @GET("/some/json/endpoint")
 Call<SomeJsonResponse>

     someJsonEndpoint();
 }X SomeJsonResponse

120. Converters interface SomeService {
 @GET("/some/proto/endpoint")
 Call<SomeProtoResponse> someProtoEndpoint(); 
 @GET("/some/json/endpoint")
 Call<SomeJsonResponse>

     someJsonEndpoint();
 }X SomeJsonResponse Proto? No!

121. Converters interface SomeService {
 @GET("/some/proto/endpoint")
 Call<SomeProtoResponse> someProtoEndpoint(); 
 @GET("/some/json/endpoint")
 Call<SomeJsonResponse>

     someJsonEndpoint();
 }X SomeJsonResponse Proto? No! JSON? Yes!

122. Retrofit 2 • Call encapsulates single request/response interaction • Parameterized

     Response object • Dynamic URL parameter • Multiple, efficient converters • Multiple, pluggable execution mechanisms

123. Execution Mechanisms interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String

     owner,
 @Path("repo") String repo);
 }X

124. Execution Mechanisms interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String

     owner,
 @Path("repo") String repo); 
 @GET("/repos/{owner}/{repo}/contributors")
 Observable<List<Contributor>> repoContributors2(
 @Path("owner") String owner,
 @Path("repo") String repo); 
 @GET("/repos/{owner}/{repo}/contributors")
 Future<List<Contributor>> repoContributors3(
 @Path("owner") String owner,
 @Path("repo") String repo);
 }X

125. Execution Mechanisms interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(..); 
 @GET("/repos/{owner}/{repo}/contributors")


     Observable<List<Contributor>> repoContributors2(..); 
 @GET("/repos/{owner}/{repo}/contributors")
 Future<List<Contributor>> repoContributors3(..);
 }X Call

126. Execution Mechanisms interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(..); 
 @GET("/repos/{owner}/{repo}/contributors")


     Observable<List<Contributor>> repoContributors2(..); 
 @GET("/repos/{owner}/{repo}/contributors")
 Future<List<Contributor>> repoContributors3(..);
 }X Call

127. Execution Mechanisms interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(..); 
 @GET("/repos/{owner}/{repo}/contributors")


     Observable<List<Contributor>> repoContributors2(..); 
 @GET("/repos/{owner}/{repo}/contributors")
 Future<List<Contributor>> repoContributors3(..);
 }X Call RxJava? No!

128. Execution Mechanisms interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(..); 
 @GET("/repos/{owner}/{repo}/contributors")


     Observable<List<Contributor>> repoContributors2(..); 
 @GET("/repos/{owner}/{repo}/contributors")
 Future<List<Contributor>> repoContributors3(..);
 }X Call RxJava? No! Call? Yes!

129. Execution Mechanisms interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(..); 
 @GET("/repos/{owner}/{repo}/contributors")


     Observable<List<Contributor>> repoContributors2(..); 
 @GET("/repos/{owner}/{repo}/contributors")
 Future<List<Contributor>> repoContributors3(..);
 }X Observable

130. Execution Mechanisms interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(..); 
 @GET("/repos/{owner}/{repo}/contributors")


     Observable<List<Contributor>> repoContributors2(..); 
 @GET("/repos/{owner}/{repo}/contributors")
 Future<List<Contributor>> repoContributors3(..);
 }X Observable RxJava? Yes!

131. Execution Mechanisms interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(..); 
 @GET("/repos/{owner}/{repo}/contributors")


     Observable<List<Contributor>> repoContributors2(..); 
 @GET("/repos/{owner}/{repo}/contributors")
 Future<List<Contributor>> repoContributors3(..);
 }X Future

132. Execution Mechanisms interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(..); 
 @GET("/repos/{owner}/{repo}/contributors")


     Observable<List<Contributor>> repoContributors2(..); 
 @GET("/repos/{owner}/{repo}/contributors")
 Future<List<Contributor>> repoContributors3(..);
 }X Future RxJava? No!

133. Execution Mechanisms interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(..); 
 @GET("/repos/{owner}/{repo}/contributors")


     Observable<List<Contributor>> repoContributors2(..); 
 @GET("/repos/{owner}/{repo}/contributors")
 Future<List<Contributor>> repoContributors3(..);
 }X Future RxJava? No! Call? No!

134. Execution Mechanisms interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(..); 
 @GET("/repos/{owner}/{repo}/contributors")


     Observable<List<Contributor>> repoContributors2(..); 
 @GET("/repos/{owner}/{repo}/contributors")
 Future<List<Contributor>> repoContributors3(..);
 }X Future RxJava? No! Call? No! Throw!

135. Retrofit 2 • Call encapsulates single request/response interaction • Parameterized

     Response object • Dynamic URL parameter • Multiple, efficient converters • Multiple, pluggable execution mechanisms

136. Powered by OkHttp

137. Powered by OkHttp • In 2012 we needed client abstractions.

138. Powered by OkHttp • In 2012 we needed client abstractions.

     • In 2012 we needed request/response abstractions.

139. Powered by OkHttp • In 2012 we needed client abstractions.

     • In 2012 we needed request/response abstractions. • In 2012 we needed header abstractions.

140. Powered by OkHttp • In 2012 we needed client abstractions.

     • In 2012 we needed request/response abstractions. • In 2012 we needed header abstractions. • It's 2015. OkHttp is small, lean, focused, and full-featured.

141. Powered by OkHttp

142. Powered by OkHttp & Okio bit.ly/ok-libs

143. Retrofit

144. Retrofit OkHttp

145. Retrofit OkHttp Socket

146. Retrofit OkHttp BufferedSource BufferedSink Socket

147. Retrofit OkHttp BufferedSource BufferedSink RequestBody ResponseBody Socket

148. Retrofit OkHttp MoshiConverter BufferedSource BufferedSink RequestBody ResponseBody Socket

149. Retrofit OkHttp MoshiConverter BufferedSource BufferedSink RequestBody ResponseBody Socket Moshi

150. Retrofit OkHttp MoshiConverter BufferedSource BufferedSink RequestBody ResponseBody Socket Moshi BufferedSink

     BufferedSource <T>

151. Retrofit OkHttp MoshiConverter BufferedSource BufferedSink RequestBody ResponseBody <T> RequestBody ResponseBody

     Socket Moshi BufferedSink BufferedSource <T>

152. Retrofit OkHttp MoshiConverter BufferedSource BufferedSink RequestBody ResponseBody <T> MyService RequestBody

     ResponseBody Socket Moshi BufferedSink BufferedSource <T>

153. Retrofit OkHttp MoshiConverter BufferedSource BufferedSink RequestBody ResponseBody <T> MyService RequestBody

     ResponseBody Socket myEndpoint() Moshi BufferedSink BufferedSource <T>

154. Retrofit OkHttp MoshiConverter BufferedSource BufferedSink RequestBody ResponseBody <T> MyService RequestBody

     ResponseBody Socket execute() myEndpoint() Moshi BufferedSink BufferedSource <T>

155. Retrofit OkHttp MoshiConverter BufferedSource BufferedSink RequestBody ResponseBody <T> MyService RequestBody

     ResponseBody Socket execute() myEndpoint() Moshi BufferedSink BufferedSource <T>

156. Retrofit OkHttp MoshiConverter BufferedSource BufferedSink RequestBody ResponseBody <T> MyService RequestBody

     ResponseBody Socket execute() myEndpoint() Moshi BufferedSink BufferedSource <T>

157. Retrofit OkHttp MoshiConverter BufferedSource BufferedSink RequestBody ResponseBody <T> MyService RequestBody

     ResponseBody Socket execute() myEndpoint() Moshi BufferedSink BufferedSource <T>

158. Retrofit OkHttp MoshiConverter BufferedSource BufferedSink RequestBody ResponseBody <T> MyService RequestBody

     ResponseBody Socket execute() myEndpoint() Moshi BufferedSink BufferedSource <T>

159. Retrofit OkHttp MoshiConverter BufferedSource BufferedSink RequestBody ResponseBody <T> MyService RequestBody

     ResponseBody Socket execute() myEndpoint() Moshi BufferedSink BufferedSource <T>

160. Retrofit OkHttp MoshiConverter BufferedSource BufferedSink RequestBody ResponseBody <T> MyService RequestBody

     ResponseBody Socket execute() myEndpoint() Moshi BufferedSink BufferedSource <T>

161. Retrofit OkHttp MoshiConverter BufferedSource BufferedSink RequestBody ResponseBody <T> MyService RequestBody

     ResponseBody Socket execute() myEndpoint() Moshi BufferedSink BufferedSource <T>

162. Retrofit OkHttp MoshiConverter BufferedSource BufferedSink RequestBody ResponseBody <T> MyService RequestBody

     ResponseBody Socket execute() myEndpoint() Moshi BufferedSink BufferedSource <T>

163. Retrofit OkHttp MoshiConverter BufferedSource BufferedSink RequestBody ResponseBody <T> MyService RequestBody

     ResponseBody Socket execute() myEndpoint() Moshi BufferedSink BufferedSource <T>

164. Retrofit OkHttp MoshiConverter BufferedSource BufferedSink RequestBody ResponseBody <T> MyService RequestBody

     ResponseBody Socket execute() myEndpoint() Moshi BufferedSink BufferedSource <T>

165. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com") .build();

166. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com") .build(); interface GitHubService

     {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String owner,
 @Path("repo") String repo);
 }

167. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com") .build(); interface GitHubService

     {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String owner,
 @Path("repo") String repo);
 } GitHubService gitHubService = retrofit.create(GitHubService.class);

168. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com") .build(); interface GitHubService

     {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String owner,
 @Path("repo") String repo);
 } // https://api.github.com/repos/square/retrofit/contributors

169. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com") .build(); interface GitHubService

     {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String owner,
 @Path("repo") String repo);
 } // https://api.github.com/repos/square/retrofit/contributors HttpUrl

170. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com") .build(); interface GitHubService

     {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String owner,
 @Path("repo") String repo);
 } // https://api.github.com/repos/square/retrofit/contributors HttpUrl .resolve()

171. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com") .build(); interface GitHubService

     {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String owner,
 @Path("repo") String repo);
 }

172. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com/v3/") .build(); interface GitHubService

     {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String owner,
 @Path("repo") String repo);
 }

173. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com/v3/") .build(); interface GitHubService

     {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String owner,
 @Path("repo") String repo);
 }

174. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com/v3/") .build(); interface GitHubService

     {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String owner,
 @Path("repo") String repo);
 } // https://api.github.com/repos/square/retrofit/contributors

175. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com/v3/") .build(); interface GitHubService

     {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String owner,
 @Path("repo") String repo);
 } // https://api.github.com/repos/square/retrofit/contributors HttpUrl .resolve()

176. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com/v3/") .build(); interface GitHubService

     {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String owner,
 @Path("repo") String repo);
 }X

177. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com/v3/") .build(); interface GitHubService

     {
 @GET("repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String owner,
 @Path("repo") String repo);
 }X

178. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com/v3/") .build(); interface GitHubService

     {
 @GET("repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String owner,
 @Path("repo") String repo);
 }

179. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com/v3/") .build(); interface GitHubService

     {
 @GET("repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(
 @Path("owner") String owner,
 @Path("repo") String repo);
 } // https://api.github.com/v3/repos/square/retrofit/contributors

180. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com") .build();

181. Setup OkHttpClient client = new OkHttpClient(); Retrofit retrofit = new

     Retrofit.Builder() .baseUrl("https://api.github.com") .client(client) .build();

182. Setup OkHttpClient client = new OkHttpClient(); client.interceptors().add(..); Retrofit retrofit =

     new Retrofit.Builder() .baseUrl("https://api.github.com") .client(client) .build();

183. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com") .build();

184. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com") .addConverterFactory(GsonConverterFactory.create()) .build();

185. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com") .addConverterFactory(GsonConverterFactory.create()) .addConverterFactory(ProtoConverterFactory.create()) .build();

186. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com") .addConverterFactory(ProtoConverterFactory.create()) .addConverterFactory(GsonConverterFactory.create()) .build();

187. Setup Retrofit retrofit = new Retrofit.Builder() .baseUrl("https://api.github.com") .addConverterFactory(ProtoConverterFactory.create()) .addConverterFactory(GsonConverterFactory.create()) .addCallAdapterFactory(RxJavaCallAdapterFactory.create())

     .build();

188. Extensibility • Converter.Factory • CallAdapter.Factory

189. Converter.Factory interface SomeService {
 @GET("/some/proto/endpoint")
 Call<SomeProtoResponse> someProtoEndpoint(); 
 @GET("/some/json/endpoint")
 Call<SomeJsonResponse>

     someJsonEndpoint();
 }X SomeJsonResponse Proto? No! JSON? Yes!

190. Converter.Factory interface Converter<T> { interface Factory { Converter<?> create(Type type);

     } }X SomeJsonResponse Proto? No! JSON? Yes!

191. Converter.Factory SomeJsonResponse Proto? No! JSON? Yes!

192. Converter.Factory class ProtoConverterFactory { Converter<?> create(Type type); }X SomeJsonResponse null

     No! JSON? Yes!

193. JSON Converter.Factory class ProtoConverterFactory { Converter<?> create(Type type); }X SomeJsonResponse

     null No! Converter<?> Yes! class GsonConverterFactory { Converter<?> create(Type type); }X

194. Converter.Factory interface Converter<T> { interface Factory { Converter<?> create(Type type);

     }X }X

195. Converter.Factory interface Converter<T> { interface Factory { Converter<?> create(Type type);

     }X T fromBody(ResponseBody body); RequestBody toBody(T value); }X

196. Extensibility • Converter.Factory • CallAdapter.Factory

197. CallAdapter.Factory interface GitHubService {
 @GET("/repos/{owner}/{repo}/contributors")
 Call<List<Contributor>> repoContributors(..); 
 @GET("/repos/{owner}/{repo}/contributors")
 Observable<List<Contributor>>

     repoContributors2(..);
 }X Call RxJava? No! Call? Yes!

198. CallAdapter.Factory interface CallAdapter<T> { interface Factory { CallAdapter<?> create(Type type);

     }
 }X Call RxJava? No! Call? Yes!

199. CallAdapter.Factory Call RxJava? No! Call? Yes!

200. CallAdapter.Factory Call Call? Yes! class RxJavaCallAdapterFactory { CallAdapter<?> create(Type type);

     }X null No!

201. CallAdapter.Factory Call class RxJavaCallAdapterFactory { CallAdapter<?> create(Type type); }X null

     No! JSON CallAdapter<?> Yes! class CallAdapterFactory { CallAdapter<?> create(Type type); }X

202. CallAdapter.Factory interface CallAdapter<T> { interface Factory { CallAdapter<?> create(Type type);

     }X }X

203. CallAdapter.Factory interface CallAdapter<T> { interface Factory { CallAdapter<?> create(Type type);

     }X Type responseType(); Object adapt(Call<T> value); }X

204. Extensibility • Converter.Factory • CallAdapter.Factory

205. Under Construction

206. Under Construction • Parameter handlers

207. Under Construction • Parameter handlers • Logging?

208. Under Construction • Parameter handlers • Logging? • Finalizing mock

     module

209. Under Construction • Parameter handlers • Logging? • Finalizing mock

     module • Documentation

210. Under Construction • Parameter handlers • Logging? • Finalizing mock

     module • Documentation • WebSockets! (in v2.1)

211. Release?

212. Release? dependencies {
 compile 'com.squareup.retrofit:retrofit:2.0.0-beta1' compile 'com.squareup.retrofit:converter-gson:2.0.0-beta1' compile 'com.squareup.retrofit:adapter-rxjava:2.0.0-beta1' }

213. jakewharton jakewharton twitter.com/ google.com/+ .com Retrofit Two jakewharton