一、Gradle配置

compile 'com.squareup.retrofit2:retrofit:2.0.0-beta4'
compile 'com.squareup.retrofit2:converter-gson:2.0.0-beta4'

二、使用Retrofit

1.初始化

Retrofit retrofit = new Retrofit.Builder()
          .baseUrl("http://localhost:8080/")
          .addConverterFactory(GsonConverterFactory.create())
          .build();

2.编写API

public interface ApiManager {
    @GET("URL")
    <T> Call<T> request(@Query("name") String name, @Query("password") String pw);
}

3.调用API

ApiManager manager=retrofit.create(ApiManager.class);
Call<T> call=manager.request("admin","123");
call.enqueue(new Callback<T>());//enqueue为异步调用,execute为同步调用

4.API编写示例

/**
* 单个请求参数
*/
@GET("URL")
<T> Call<T> request(@Query("name") String name, @Query("password") String pw);

/**
* 多个请求参数
 */
@GET("URL")
<T> Call<T> request(@QueryMap Map<String, String> map);

/**
* 表单提交
*/
@FormUrlEncoded
@POST("URL")
<T> Call<T> postForm(@FieldMap Map<String, String> map);

/**
* 对象提交
*/
@POST("URL")
<T> Call<T> postBody(@Body Objects objects);

/**
* 单个文件上传
*/
@Multipart
@POST("URL")
Call<RequestBody> uploadFlie(@Part("description") RequestBody description, @Part("files") MultipartBody.Part file);

/**
* 多个文件上传
*/
@Multipart
@POST("{URL}")
<T> Call<T> uploadFiles(@Path("URL") String url, @PartMap() Map<String, RequestBody> maps);

5.取消请求

call.cancel();

三、拦截器

1.Log拦截器

//通过添加网络拦截器的方式来开启Log日志
Retrofit retrofit = new Retrofit.Builder()
    .client(new OkHttpClient.Builder()
    .addNetworkInterceptor(new HttpLoggingInterceptor()
    .setLevel(HttpLoggingInterceptor.Level.HEADERS))
    .build());
//Level.NONE:关闭日志
//Level.BASIC:基本输出日志
//Level.HEADERS:请求日志
//Level.BODY:主体日志

2.Head拦截器

//多个请求头添加
new Retrofit.Builder()
           .addConverterFactory(GsonConverterFactory.create())
           .client(new OkHttpClient.Builder()
           .addInterceptor(new Interceptor() {
                @Override
                public Response intercept(Chain chain) throws IOException {
                           Request request = chain.request()
                                   .newBuilder()
                                   .addHeader("mac", "f8:00:ea:10:45")
                                   .addHeader("uuid", "gdeflatfgfg5454545e")
                                   .addHeader("netWork", "wifi")
                                   .build();
                           return chain.proceed(request);
                       }
                   })
                   .build();

//单个请求头添加
@Headers({ "Accept: application/vnd.github.v3.full+json", "User-Agent: Retrofit-your-App"})
@GET("URL")
<T> Call<T> request(@Query("name") String name, @Query("password") String password);