XListView

import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;

import com.bawei.jane.mxlistview.view.XListView;
import com.google.gson.Gson;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import adapter.MyAdapter;
import bean.Result;

public class MainActivity extends AppCompatActivity {


    private XListView xlv;
    private  int pageIndex=1;//第一页的数据
    private String urlpart="http://www.yulin520.com/a2a/impressApi/news/mergeList?pageSize=10&page=";

    private String url =urlpart + pageIndex;

    private MyAdapter adapter;
    private List<Result.DataBean>data = new ArrayList<>();
    private int operType = 1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //初始化控件
        xlv = findViewById(R.id.xlv);
        //对xlistview进行设置
        xlv.setPullLoadEnable(true);//上拉加载更多
        xlv.setPullRefreshEnable(true);//下拉刷新

        //设置接口
        xlv.setXListViewListener(new XListView.IXListViewListener() {
            @Override
            public void onRefresh() {//刷新
                //刷新时，重新请求第一页的数据
                pageIndex = 1;
                url = urlpart+pageIndex;
                //重新赋值
                operType = 1;
                MyTask myTask = new MyTask();
                myTask.execute(url);

            }

            @Override
            public void onLoadMore() {//加载更多
                //页数增加
                pageIndex++;
                url = urlpart+pageIndex;
                //重新赋值
                operType =2;
                MyTask task = new MyTask();
                task.execute(url);

            }
        });

     //进行网络请求
        MyTask myTask = new MyTask();
        myTask.execute(url);
    }
      class    MyTask  extends AsyncTask<String,Void,String>{
          @Override
          protected String doInBackground(String... strings) {
              StringBuilder builder = new StringBuilder();
              try {
                  URL url = new URL(strings[0]);
                 HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                  connection.setRequestMethod("GET");
                  connection.setReadTimeout(5000);
                  connection.setReadTimeout(5000);
                  if (connection.getResponseCode()==200){
                      InputStream inputStream = connection.getInputStream();
                      BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
                      String str;
                      while ((str=reader.readLine())!=null){
                          builder.append(str);
                      }
                      reader.close();
                  }

              } catch (Exception e) {
                  e.printStackTrace();
              }
              return builder.toString();
          }

          @Override
          protected void onPostExecute(String s) {
              Gson gson =new Gson();
              Result result = gson.fromJson(s, Result.class);



              if (operType==1) {//代表刷新操作
                  data.clear();//清空原有的集合数据
              }
              //增加新的数据集合到原来的集合对象中
              data.addAll(result.getData());
              setAdapter();
              //关闭头尾布局
              if (operType==1){
                  xlv.stopRefresh();//关闭头布局
                  Date date = new Date(System.currentTimeMillis());//获取当前时间
                  SimpleDateFormat sf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//格式化时间
                  String refreShTime = sf.format(date);
                  xlv.setRefreshTime(refreShTime);//设置刷新时间

              }else{
                  xlv.stopLoadMore();//关闭尾布局
              }

              }

          }
          public void setAdapter(){
        if (adapter ==null){
            adapter = new MyAdapter(data,MainActivity.this);
            xlv.setAdapter(adapter);
        }else{
            adapter.notifyDataSetChanged();
        }
          }
      }