使用前需要在Gradle Script中的build gradle中引入：

compile 'com.squareup.okio:okio:1.13.0'

compile 'com.squareup.okhttp3:okhttp:3.9.0'

GET

//创建OkHttpClient对象

OkHttpClient okHttpClient = new OkHttpClient.Builder()

.connectTimeout(10, TimeUnit.SECONDS)

.writeTimeout(10,TimeUnit.SECONDS)

.readTimeout(20, TimeUnit.SECONDS)

.build();

final Request request = new Request.Builder()

.url("http://172.20.192.168:8080/getbookByFrom?name=android基础&price=50")//请求的url

.get()//设置请求方式，get()/post() 查看Builder()方法知，在构建时默认设置请求方式为GET

.build(); //构建一个请求Request对象

//创建/Call

Call call = okHttpClient.newCall(request);

//加入队列 异步操作

call.enqueue(new Callback() {

//请求错误回调方法

@Override

public void onFailure(Call call, IOException e) {

System.out.println("连接失败");

}

//异步请求(非主线程)

@Override

public void onResponse(Call call, Response response) throws IOException {

if(response.code()==200) {

System.out.println(response.body().string());

}

});

POST(json方式)

OkHttpClient okHttpClient = new OkHttpClient.Builder()

.connectTimeout(10, TimeUnit.SECONDS)

.writeTimeout(10,TimeUnit.SECONDS)

.readTimeout(20, TimeUnit.SECONDS)

.build();

Book book = new Book();

book.setName("android基础");

book.setPrice(59);

//使用Gson 添加 依赖 compile 'com.google.code.gson:gson:2.8.1'

Gson gson = new Gson();

//使用Gson将对象转换为json字符串

String json = gson.toJson(book);

//MediaType 设置Content-Type 标头中包含的媒体类型值

RequestBody requestBody = FormBody.create(MediaType.parse("application/json; charset=utf-8")

, json);

Request request = new Request.Builder()

.url("http://172.20.192.168:8080/getbookByJson")//请求的url

.post(requestBody)

.build();

//创建/Call

Call call = okHttpClient.newCall(request);

//加入队列 异步操作

call.enqueue(new Callback() {

//请求错误回调方法

@Override

public void onFailure(Call call, IOException e) {

System.out.println("连接失败");

}

@Override

public void onResponse(Call call, Response response) throws IOException {

System.out.println(response.body().string());

}

});

关于将对象转换为json字符串，除了使用Gson还可以用JSONObject：

public static final MediaType JSON=MediaType.parse("application/json; charset=utf-8");

JSONObject jsonObject = new JSONObject();

try {

//example: {'likes':['体育','政治'...]}

jsonObject.put("likes",selectedThemes);

} catch (JSONException e) {

e.printStackTrace();

}

//创建一个RequestBody(参数1：数据类型 参数2传递的json串)

RequestBody requestBody = RequestBody.create(JSON, jsonObject.toString());

开发过程中遇到传json需要带上authentication的问题，然后在Stack Overflow上找到了解决方法——使用Interceptor。

import java.io.IOException;

import okhttp3.Credentials;

import okhttp3.Interceptor;

import okhttp3.Request;

import okhttp3.Response;

public class BasicAuthInterceptor implements Interceptor {

private String credentials;

public BasicAuthInterceptor(String user, String password) {

this.credentials = Credentials.basic(user, password);

}

@Override

public Response intercept(Chain chain) throws IOException {

Request request = chain.request();

Request authenticatedRequest = request.newBuilder()

.header("Authorization", credentials).build();

return chain.proceed(authenticatedRequest);

}

}

这样就把username和password放进了authentication里。然后把这个Interceptor加到OkHttpClient就可以了。

OkHttpClient client = new OkHttpClient.Builder()

.addInterceptor(new BasicAuthInterceptor(username, password))

.build();