工具類

public class MyTask extends AsyncTask<String,Void,String> {
    private MyHuidiao huidiao;
    public MyTask(MyHuidiao huidiao){
        this.huidiao = huidiao;
    }
    @Override
    protected String doInBackground(String... strings) {
        try {
            URL url = new URL(strings[0]);
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setRequestMethod("GET");
            urlConnection.setReadTimeout(5000);
            urlConnection.setConnectTimeout(5000);
            int code = urlConnection.getResponseCode();
            if(code == 200){
                InputStream inputStream = urlConnection.getInputStream();
                String s = getString(inputStream);
                return s;
            }

        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(String s) {
        huidiao.MyJson(s);
        super.onPostExecute(s);
    }
    public String getString(InputStream inputStream){
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        byte[] b = new byte[1024];
        int len = -1;
        try {
            while((len=inputStream.read(b))!=-1){
                outputStream.write(b,0,len);
            }
            String s = outputStream.toString();
            return s;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";
    }
    interface MyHuidiao{
        void MyJson(String s);
    }
}