抽取基类+pulltorefreshListView

package bw.com.rk_day20.Fragment;

import android.view.View;
import android.widget.ListView;
import android.widget.Toast;

import com.handmark.pulltorefresh.library.PullToRefreshBase;
import com.handmark.pulltorefresh.library.PullToRefreshListView;

import bw.com.rk_day20.Adapter.ApiAdapter;
import bw.com.rk_day20.Adapter.NewAdapter;
import bw.com.rk_day20.Person.ApiPerson;
import bw.com.rk_day20.Person.NewsPerson;
import bw.com.rk_day20.R;
import bw.com.rk_day20.UtilWork.NewsUtilWork;

public class Fragment2 extends BaseFragment {

    private PullToRefreshListView plv;
    private int page = 1;
    private String newsUlr = "http://api.expoon.com/AppNews/getNewsList/type/1/p/";
    private ApiAdapter adapter;
    //  private NewAdapter adapter;

    @Override
    protected void initData() {
        if (NewsUtilWork.getInstance().isNotWork(getActivity())){
            request();
        }else {
            Toast.makeText(getActivity(),"cuowu",Toast.LENGTH_SHORT).show();
        }

    }

    @Override
    protected void initView(View view) {
        plv = view.findViewById(R.id.plv);
        plv.onRefreshComplete();
      //  adapter = new NewAdapter(getActivity());
        adapter = new ApiAdapter(getActivity());
        plv.setAdapter(adapter);
        plv.setOnRefreshListener(new PullToRefreshBase.OnRefreshListener2<ListView>() {
            @Override
            public void onPullDownToRefresh(PullToRefreshBase<ListView> refreshView) {
                page = 1;
                initData();
            }

            @Override
            public void onPullUpToRefresh(PullToRefreshBase<ListView> refreshView) {
                initData();
            }
        });
        page=1;
        initData();

    }

    private void request() {
        NewsUtilWork.getInstance().getReques4(newsUlr + page, ApiPerson.class,
                new NewsUtilWork.NewsCallback<ApiPerson>() {
                    @Override
                    public void  onsccuess(ApiPerson o) {
                        if(page ==1){
                            adapter.setList(o.getData());
                        }else {
                            adapter.addList(o.getData());
                        }
                        plv.onRefreshComplete();
                        page++;
                        if (o.getData().size()<0){
                            plv.setMode(PullToRefreshBase.Mode.PULL_FROM_START);
                        }else {
                            plv.setMode(PullToRefreshBase.Mode.BOTH);
                        }
                    }

                    @Override
                    public void onFil(String msg) {
                        Toast.makeText(getActivity(),"cuowu",Toast.LENGTH_SHORT).show();
                        plv.onRefreshComplete();
                    }
                });
    }

    @Override
    protected int requeslt() {
        return R.layout.fragment2;
    }
}

2工具类

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.os.Handler;

import com.google.gson.Gson;

import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class NewsUtilWork {
    private static NewsUtilWork instance;
    private final Handler handler;

    private NewsUtilWork() {
        handler = new Handler();
    }

    public static NewsUtilWork getInstance() {
        if (instance == null){
            synchronized (NewsUtilWork.class){
                if (instance == null){
                    instance = new NewsUtilWork();
                }
            }
        }
        return instance;

    }
    public void getReques4(final String lujin, final Class classBean, final NewsCallback callback){
        new Thread(new Runnable() {
            @Override
            public void run() {
                final Object reque2 = getReque2(lujin, classBean);
                if (reque2 != null){
                    handler.post(new Runnable() {
                        @Override
                        public void run() {
                            callback.onsccuess(reque2);
                        }
                    });
                }else {
                    handler.post(new Runnable() {
                        @Override
                        public void run() {
                           callback.onFil("请求错误");
                        }
                    });
                }
            }
        }).start();
    }
/*    public void getReques3(String lujin, final Class classBean, final NewsCallback callback){
        new AsyncTask<String,Void, Object>() {
            @Override
            protected Object doInBackground(String... strings) {
                return getReque2(strings[0],classBean);
            }


            @Override
            protected void onPostExecute(Object o) {
                super.onPostExecute(o);
               if (o == null){
                   callback.onFil("请求失败");
               }else {
                   callback.onsccuess(o);
               }
            }
        }.execute(lujin);
    }*/
    public interface NewsCallback<T>{
        void onsccuess(T o);
        void onFil(String msg);
    }

    public <T> T getReque2(String lujin,Class classBean){
        Object obj;
        String reque = getReque(lujin);
        obj = new Gson().fromJson(reque, classBean);
        return (T)obj;

    }
    public String getReque(String lujin){
         String json = "";
        try {
            URL url = new URL(lujin);
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setRequestMethod("GET");
            urlConnection.setConnectTimeout(5000);
            urlConnection.setReadTimeout(5000);
            int responseCode = urlConnection.getResponseCode();
            if (responseCode == 200){
                json = getstream(urlConnection.getInputStream());

            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return json;
    }
    private String getstream(InputStream inputStream) throws Exception {
        StringBuilder sb = new StringBuilder();
        InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
        char[] buffer = new char[1024];
        for (int read = inputStreamReader.read(buffer); read != -1; read = inputStreamReader.read(buffer)) {
            sb.append(buffer, 0, read);
        }
        return sb.toString();
    }
    public boolean isNotWork(Context context){
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetworkInfo = cm.getActiveNetworkInfo();
        return activeNetworkInfo!=null&&activeNetworkInfo.isAvailable();
    }
}