[移动开发]okhttp3同步请求和异步请求小案例

学习内容：okhttp3同步请求和异步请求

OkHttp开源库进行访问

• 步骤：
  1.app/build.gradle文件在dependencies闭包中添加如下内容：
  implementation ‘com.squareup.okhttp3:okhttp:4.4.0’
  2.创建OkHttpClient类的实例
  OkHttpClient client = new OkHttpClient();
  3.创建Request对象（并设置目标地址、请求方式等）
  Request request = new Request.Builder()
  .url(“https://www.baidu.com”) //设置目标网络地址
  .get() //默认为GET请求，可以省略
  .build();
  4.调用newCall()方法来创建call对象
  Call call = client.newCall(request);
  5.发送请求并获取服务器返回的数据

学习内容：

  textView = findViewById(R.id.t1);
    OkHttpClient okHttpClient = new OkHttpClient();
    Request request = new Request.Builder().get().
            url("https://www.baidu.com").build();
    final Call call = okHttpClient.newCall(request);

同步请求：*

  textView = findViewById(R.id.t1);
    OkHttpClient okHttpClient = new OkHttpClient();
    Request request = new Request.Builder().get().
            url("https://www.baidu.com").build();
    final Call call = okHttpClient.newCall(request);
    new Thread(new Runnable() {
        @Override
        public void run() {

            try {
                Response response = call.execute();
                String sb = response.body().string();
                replace(sb);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        public void replace(String sb) {
            textView.setText(sb);
        }
    }).start();

易错点

异步请求：

**//        异步操作
        call.enqueue(new Callback() {
            @Override
            public void onFailure(@NotNull Call call, @NotNull IOException e) {
                //
//                Toast.makeText(MainActivity.this, "请求失败", Toast.LENGTH_LONG).show();
            }
            @Override
            public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
//                Toast.makeText(MainActivity.this, "请求成功", Toast.LENGTH_LONG).show();
                final String shuju = response.body().string();
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Toast.makeText(MainActivity.this, "请求成功", Toast.LENGTH_LONG).show();
                        textView.setText(shuju);
                    }
                });
            }
        });**

易错点