在github上有一个retrofit的例子，获取论坛的信息

public class ForumService {

    private static final String FORUM_SERVER_URL = "http://jsonplaceholder.typicode.com";
    private ForumApi mForumApi;

    public ForumService() {


        RequestInterceptor requestInterceptor = new RequestInterceptor() {
            @Override
            public void intercept(RequestFacade request) {
                request.addHeader("Accept", "application/json");
            }
        };

        RestAdapter restAdapter = new RestAdapter.Builder()
                .setEndpoint(FORUM_SERVER_URL)
                .setRequestInterceptor(requestInterceptor)
                .setLogLevel(RestAdapter.LogLevel.FULL)
                .build();
　　　　　//创建一个接口实例
        mForumApi = restAdapter.create(ForumApi.class);
    }

    public ForumApi getApi() {

        return mForumApi;
    }

    public interface ForumApi {

        @GET("/posts")
        public Observable<List<Post>>
            getPosts();

        @GET("/posts/{id}")
        public Observable<Post>
            getPost(@Path("id") int postId);

        @GET("/comments")
        public Observable<List<Comment>>
            getComments(@Query("postId") int postId);

        @POST("/posts")
        public Observable<Post>
            postPost(Post post);
    }
}

代码中使用DetailPresenter 和ListPresenter
程序运行时显示列表：

retrofit 用法