Okhttp3食用初级指北

Okhttp3的固定步骤是：
一：创建请求队列：
     方法一：
                    设置url
                    String url = "https://www.baidu.com";

                    设置OkHttpClient对象
                    OkHttpClient client = new OkHttpClient();

                    创建一个request
                    Request request = new Request.Builder().url(url).build();

     方法二：
            创建一个Request.Builder对象，指定url
            Request.Builder requestBuilder = new Request.Builder().url("http://www.baidu.com");

            设置请求方式默认是GET请求
            requestBuilder.method("GET",null);

            创建一个request
            Request request = requestBuilder.build();

二：发送请求
        同步请求用：Response response = client.newCall(request).execute();
        异步请求用：
                Call call = okHttpClient.newCall(request);
                call.enqueue(new Callback() {
                    @Override
                    public void onFailure(Call call, IOException e) {
                        Log.e("11111", "onFailure");
                    }

                    @Override
                    public void onResponse(Call call, Response response) throws IOException {
                        String str = response.body().string();
                        Log.e("11111", "response = " + str);

                        runOnUiThread(new Runnable() {
                            @Override
                            public void run() {
                                Log.e("11111", "异步POSE键值对请求成功");
                            }
                        });
                    }
                });

三：与文件有关要指定文件类型
MediaType MEDIA_TYPE_PNG = MediaType.parse("image/png");