呼叫方法

new MyTask(new MyTask.Icallbacks(){})；//生成返回值

myTask.execute("地址");

//介面設定

public class MyNetTask extends AsyncTask<String,Void,String> {
    //申明一個介面物件
public  Icallbacks icallbacks;
    //定義一個有帶構造方法
public MyNetTask(Icallbacks icallbacks) {
        this.icallbacks = icallbacks;
    }
    @Override
 
protected String doInBackground(String... strings) {
        StringBuilder builder=new StringBuilder();
        //1.根據url建立URL
try {
            URL url=new URL(strings[0]);
            //2.開啟連線
HttpURLConnection conn =(HttpURLConnection) url.openConnection();
            //3.設定
conn.setRequestMethod("GET"
 
);
            conn.setConnectTimeout(5000);
            conn.setReadTimeout(5000);
            //4.判斷結果碼
if(conn.getResponseCode()==200){
                //5.獲取資料
InputStream inputStream = conn.getInputStream();
                BufferedReader reader=new BufferedReader(new InputStreamReader(inputStream));
                String str;
                while 
 
((str=reader.readLine())!=null){
                    builder.append(str);
                }
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        Log.d("zzz",builder.toString());
        return builder.toString();
    }
    @Override
protected void onPostExecute(String s) {
        super.onPostExecute(s);
        //呼叫方法
icallbacks.getJsonData(s);
    }
    //定義介面
public interface Icallbacks{
        public void getJsonData(String jsonStr);
    }
}