Retrofit2 适用于Android和Java的类型安全的HTTP客户端

public interface RuquireUrlsService {
	@GET("{user}/BindingSearch/master/requireUrls.json")
	Observable<ResponseBody> getRequireUrls(@Path("user") String user);
}

		Retrofit retrofit = new Retrofit.Builder()
				.baseUrl("https://raw.githubusercontent.com/")
				.build();

//创建一个请求接口的实例对象（内部通过反射产生）
		RuquireUrlsService  service= retrofit.create(RuquireUrlsService.class);

Call<ResponseBody> call = service.getRequireUrls("rectcircle");

		call.enqueue(new Callback<ResponseBody>() {
			@Override
			public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
				try {
					System.out.println(response.body().string());
				} catch (IOException e) {
					e.printStackTrace();
				}
			}

			@Override
			public void onFailure(Call<ResponseBody> call, Throwable t) {
				t.printStackTrace();
			}
		});

{
  "version": "0.1",
  "requireUrls": [
    {
      "name": "百度",
      "url":"https://passport.baidu.com/v2/?regphonecheck&apiver=v3&phone={{phone}}",
      "loginUrl":"https://passport.baidu.com",
      "logoUrl":"https://www.baidu.com/favicon.ico",
      "prefix": "{{",
      "suffix": "}}",
      "isBind": "手机号已被注册",
      "noBind": "成功"
    }
  ]
}

@POST("/form")
@FormUrlEncoded
Call<ResponseBody> testFormUrlEncoded1(@Field("username") String name, @Field("age") int age);

/**
* Map的key作为表单的键
*/
@POST("/form")
@FormUrlEncoded
Call<ResponseBody> testFormUrlEncoded2(@FieldMap Map<String, Object> map);

/**
* {@link Part} 后面支持三种类型，{@link RequestBody}、{@link okhttp3.MultipartBody.Part} 、任意类型
* 除 {@link okhttp3.MultipartBody.Part} 以外，其它类型都必须带上表单字段({@link okhttp3.MultipartBody.Part} 中已经包含了表单字段的信息)，
*/
@POST("/form")
@Multipart
Call<ResponseBody> testFileUpload1(@Part("name") RequestBody name, @Part("age") RequestBody age, @Part MultipartBody.Part file);

Call<ResponseBody> foo(@Query("ids[]") List<Integer> ids);
//结果：ids[]=0&ids[]=1&ids[]=2

class RequireUrls<T> {
	private  String version;

	private T requireUrls;

	public String getVersion() {
		return version;
	}

	public T getRequireUrls() {
		return requireUrls;
	}

	@Override
	public String toString() {
		return "RequireUrls{" +
				"version='" + version + '\'' +
				", requireUrls=" + requireUrls +
				'}';
	}
}

class RequireUrl {
	public String name;
	public String url;
	public String loginUrl;
	public String logoUrl;
	public String prefix;
	public String suffix;

	@Override
	public String toString() {
		return "RequireUrl{" +
				"name='" + name + '\'' +
				", url='" + url + '\'' +
				", loginUrl='" + loginUrl + '\'' +
				", logoUrl='" + logoUrl + '\'' +
				", prefix='" + prefix + '\'' +
				", suffix='" + suffix + '\'' +
				", isBind='" + isBind + '\'' +
				", noBind='" + noBind + '\'' +
				'}';
	}

	public String isBind;
	public String noBind;
}

	public interface RuquireUrlsService {
		@GET("{user}/BindingSearch/master/requireUrls.json")
		Call<RequireUrls<List<RequireUrl>>> getRequireUrls(@Path("user") String user); //泛型中直接使用了实体类
	}

		Retrofit retrofit = new Retrofit.Builder()
				.baseUrl("https://raw.githubusercontent.com/")
				.addConverterFactory(GsonConverterFactory.create()) //在此加入转换器
				.build();

		//创建一个请求接口的实例对象（内部通过反射产生）
		RuquireUrlsService  service= retrofit.create(RuquireUrlsService.class);
		Call<RequireUrls<List<RequireUrl>>> call = service.getRequireUrls("rectcircle");

		call.enqueue(new Callback<RequireUrls<List<RequireUrl>>>() {
			@Override
			public void onResponse(Call<RequireUrls<List<RequireUrl>>> call, Response<RequireUrls<List<RequireUrl>>> response) {
				System.out.println(response.body().toString());
			}

			@Override
			public void onFailure(Call<RequireUrls<List<RequireUrl>>> call, Throwable t) {

			}
		});

	public interface RuquireUrlsService {
		@GET("{user}/BindingSearch/master/requireUrls.json")
		Observable<RequireUrls<List<RequireUrl>>> getRequireUrls(@Path("user") String user); //返回的是一个Observable
	}

		Retrofit retrofit = new Retrofit.Builder()
				.baseUrl("https://raw.githubusercontent.com/")
				.addConverterFactory(GsonConverterFactory.create())
				.addCallAdapterFactory(RxJava2CallAdapterFactory.create()) //引入了对Rxjava的支持
				.build();

//创建一个请求接口的实例对象（内部通过反射产生）
RuquireUrlsService  service= retrofit.create(RuquireUrlsService.class);

Observable<RequireUrls<List<RequireUrl>>> observable =  service.getRequireUrls("rectcircle");

		observable
				.subscribeOn(Schedulers.io())
//				.observeOn(AndroidSchedulers.mainThread()); //安卓要启用这一行
				.subscribe(new Observer<RequireUrls<List<RequireUrl>>>(){
					@Override
					public void onSubscribe(Disposable d) {

					}

					@Override
					public void onNext(RequireUrls<List<RequireUrl>> s) {
						System.out.println((s.toString()));
						//在这里处理数据
					}

					@Override
					public void onError(Throwable e) {

					}

					@Override
					public void onComplete() {

					}
				});
				Thread.sleep(3000); //java main测试加入此行，安卓不需要

	public interface HomePageService {
		@GET("/")
		Observable<String> getHome();
	}

	public static void main(String[] args) throws InterruptedException {
		Retrofit retrofit = new Retrofit.Builder()
				.baseUrl("https://www.baidu.com/")
				.addConverterFactory(ScalarsConverterFactory.create()) //使用scalar转换器，否则报错
				.addCallAdapterFactory(RxJava2CallAdapterFactory.create())
				.build();

		retrofit.create(HomePageService.class)
				.getHome()
				.subscribe(System.out::println);
	}

public interface Converter<F, T> {
	// 实现从 F(rom) 到 T(o)的转换
	T convert(F value) throws IOException;

	// 用于向Retrofit提供相应Converter的工厂
	abstract class Factory {
		// 这里创建从ResponseBody其它类型的Converter，如果不能处理返回null
		// 主要用于对响应体的处理
		public Converter<ResponseBody, ?> responseBodyConverter(Type type, Annotation[] annotations,
																														Retrofit retrofit) {
			return null;
		}

		// 在这里创建 从自定类型到ResponseBody 的Converter,不能处理就返回null，
		// 主要用于对Part、PartMap、Body注解的处理
		public Converter<?, RequestBody> requestBodyConverter(Type type,
																													Annotation[] parameterAnnotations, Annotation[] methodAnnotations, Retrofit retrofit) {
			return null;
		}

		// 这里用于对Field、FieldMap、Header、Path、Query、QueryMap注解的处理
		// Retrfofit对于上面的几个注解默认使用的是调用toString方法
		public Converter<?, String> stringConverter(Type type, Annotation[] annotations,
																								Retrofit retrofit) {
			return null;
		}

	}
}