Use of XlistView

public class MainActivity extends AppCompatActivity {
    private XListView xlistview;
    private int page=1;
    private int oper=1;
    private String myurl="http://data.v.qq.com/videocms/getNewsvideoList.php?ref=pclient&appkey=6UkwV9DeHr9_PC&vsite=" +
            "new_vshou&ename=new_vs_feature&report=web.news&_="+page;
    private  List<Lei.DataBean.ContentBean> datad;
    private MaAdapter maAdapter ;

    @Override
protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);    
        setContentView(R.layout.activity_main);
        xlistview=findViewById(R.id.xlv);
        datad=new ArrayList<>();
        initDeta();
        ReIntect();
    }

    private void ReIntect() {
        MaData maData = new MaData ();
        maData.execute(myurl);
    }
    private class MaData extends AsyncTask<String,Integer,String>{

        @Override
protected String doInBackground(String... strings) {
            try {        
                URL url = new URL(strings[0]);
                HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
                urlConnection.setReadTimeout(5000);
                urlConnection.setRequestMethod("GET");
                urlConnection.setConnectTimeout(5000);
               if(urlConnection.getResponseCode()==200){
                   InputStream inputStream = urlConnection.getInputStream();
                   String ss=StreamToString(inputStream);
                   return ss;
               }
            } catch (Exception e) {
                e.printStackTrace ();
            }
            return null;
        }

        @Override
protected void onPostExecute(String s) {
            super.onPostExecute(s);        
            Gson gson = new Gson ();
            String replase=s.replace("content(","").replace(");","");
           // Lei.DataBean data = new Lei().getData();
            Lei lei = gson.fromJson(replase, Lei.class);
            List<Lei.DataBean.ContentBean> list = lei.getData().getContent();

            //List<Lei.DataBean.ContentBean> list = data.getContent();
if(oper==1){
                datad.clear();            
            }
            datad.addAll(list);
            serMyAdapter ();
            if ( oper == 1 ){
                 xlistview .stopLoadMore ();
                 //Set the current time
                 Date date = new Date(());
                SimpleDateFormat sdf = new SimpleDateFormat("MM-dd HH:mm:ss");
                String format = sdf.format(date);
                xlistview.setRefreshTime(format);
            }else{
                xlistview.stopLoadMore();

            }
        }
    }

    private void serMyAdapter () {
         if ( maAdapter == null ) {
             maAdapter = new MaAdapter ( datad , MainActivity. this );
            xlistview .setAdapter ( maAdapter );
        }else{
            maAdapter.notifyDataSetChanged();
        }
    }

    private String StreamToString(InputStream inputStream) {

        StringBuilder stb=new StringBuilder();
        String str;
        BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
        try {
            while((str=reader.readLine())!=null){
                stb.append(str);
            }
        } catch (IOException e) {
            e.printStackTrace ();
        }
        return stb.toString();
    }


    private void initDeta() {
        xlistview.setPullLoadEnable(true);
        xlistview.setPullRefreshEnable(true);
        xlistview.setXListViewListener(new XListView.IXListViewListener() {
            @Override
public void onRefresh() {
                page=1;
                oper=1;
                myurl="http://data.v.qq.com/videocms/getNewsvideoList.php?ref=pclient&appkey=6UkwV9DeHr9_PC&vsite=" +
                                    "new_vshou&ename=new_vs_feature&report=web.news&_="+page;
                ReIntect();
            }

            @Override
public void onLoadMore() {
                oper=2;
                page++;
                myurl="http://data.v.qq.com/videocms/getNewsvideoList.php?ref=pclient&appkey=6UkwV9DeHr9_PC&vsite=" +
                        "new_vshou&ename=new_vs_feature&report=web.news&_="+page;            
                ReIntect();
            }
        });
    }


}