如何使用OkHttp3进行GET和POST请求：包括JSON参数传输与表单数据提交示例

get 请求

        //创建OkHttpClient对象
        OkHttpClient okHttpClient = new OkHttpClient.Builder()
                .connectTimeout(10, TimeUnit.SECONDS) // 超时设置
                .writeTimeout(10, TimeUnit.SECONDS)
                .readTimeout(20, TimeUnit.SECONDS)
                .build();

        final Request request = new Request.Builder()
                .url("http://XXXX.com")
                .addHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.111 Safari/537.36")
                .addHeader("Host", "XXXX.com")
                .get()
                .build(); 

        Call call = okHttpClient.newCall(request);
        //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 请求 -- form表单提交

        OkHttpClient okHttpClient = new OkHttpClient.Builder()
                .connectTimeout(10, TimeUnit.SECONDS)
                .writeTimeout(10, TimeUnit.SECONDS)
                .readTimeout(20, TimeUnit.SECONDS)
                .build();

        //post方式提交的数据
        FormBody formBody = new FormBody.Builder()
                .add("t", "test")
                .build();

        final Request request = new Request.Builder()
                .url("http://XXX.com")//请求的url
                .addHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.111 Safari/537.36")
                .addHeader("Host", "XXXX.com")
                .post(formBody)
                .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 {
                if (response.code() == 200) {
                    System.out.println(response.body().string());
                }
            }
        });

post 请求 -- json格式提交

OkHttpClient okHttpClient = new OkHttpClient.Builder()
                .connectTimeout(10, TimeUnit.SECONDS)
                .writeTimeout(10, TimeUnit.SECONDS)
                .readTimeout(20, TimeUnit.SECONDS)
                .build();

        JSONObject json = new JSONObject();
        try {
            json.put("t", "test");
        } catch (JSONException e) {
            e.printStackTrace();
        }

        //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://XXX.com")//请求的url
                .addHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.111 Safari/537.36")
                .addHeader("Host", "XXXX.com")
                .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());
            }
        });