AsyncTask的二次封装类

最新推荐文章于 2021-05-27 07:05:04 发布

原创最新推荐文章于 2021-05-27 07:05:04 发布 · 261 阅读

CC 4.0 BY-SA版权

本文介绍了一个基于AsyncTask的异步任务处理类，该类通过GET请求从指定URL获取JSON数据，并使用Gson库进行解析。文章展示了如何定义接口回调、执行网络请求、处理响应数据以及解析JSON。

public class Asny extends AsyncTask<String,Void,String> {
    //2.申明接口对象
    private IcallBack icallBack;
    //3.传递一个接口实现类
    public Asny(IcallBack icallBack) {
        this.icallBack = icallBack;
    }

    @Override
    protected String doInBackground(String... strings) {

        URL url= null;
        try {
            url = new URL(strings[0]);
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();

            urlConnection.setRequestMethod("GET");
            urlConnection.setReadTimeout(5000);
            urlConnection.setConnectTimeout(5000);

            if(urlConnection.getResponseCode()==200) {
                InputStream inputStream = urlConnection.getInputStream();

                String s = streamToString(inputStream);
                return s;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }


        return null;
    }

    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);
        icallBack.getJson(s);

    }


    //1.定义接口
    public interface IcallBack{
        //只有申明，没有实现
        void getJson(String jsonData);

    }

    /**
     * 将流转换成String
     * @param stream
     */
    private String streamToString(InputStream stream) {
        StringBuilder sbuilder=new StringBuilder();
        String str;
        BufferedReader reader=new BufferedReader(new InputStreamReader(stream));

        try {
            while ((str=reader.readLine())!=null){
                sbuilder.append(str);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return  sbuilder.toString();

    }

}

//调用接口

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Asny asny =  new Asny(new Asny.IcallBack() {
            @Override
            public void getJson(String jsonData) {
                Gson gson = new Gson();
                Result result = gson.fromJson(jsonData, Result.class);
                List<Result.NewslistBean> newslist = result.getNewslist();
                Log.i("TAG", "getJson: "+newslist.size());
                ///关闭头尾布局
                //plv.onRefreshComplete();
            }
        });

        asny.execute("http://api.tianapi.com/meinv/?key=11ea949d63cdcfc91838cb62177c0f00&num=10");
    }
}