封裝工具類

package com.example.pullshuaixn;

import android.annotation.SuppressLint;
import android.os.AsyncTask;

import com.google.gson.Gson;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

import javax.security.auth.callback.Callback;

public class NetUtil {

    private static NetUtil netUtil;

    public  NetUtil(){

    }

    public static NetUtil getNetUtil(){
        if (netUtil == null){
            netUtil = new NetUtil();
        }
        return  netUtil;
    }

    public interface  CallBak<T>{
        void  onsuccess(T t);
    }

    @SuppressLint("StaticFieldLeak")
    public  void requsetData(String strurl, final Class clazz, final CallBak callback){
        new AsyncTask<String, Void, Object>() {
            @Override
            protected Object doInBackground(String... strings) {
                return requsetData( strings[0],clazz );
            }

            @Override
            protected void onPostExecute(Object o) {
                callback.onsuccess( o );
            }
        }.execute( strurl );
    }


    private <T>T requsetData(String string, Class clazz) {
        return (T) new Gson().fromJson( requsetData(string),clazz );
    }

    private  String requsetData(String str){
        try {
            URL url = new URL(str);
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setRequestMethod("GET");
            urlConnection.setConnectTimeout(5000);
            urlConnection.setReadTimeout(5000);
            int responseCode = urlConnection.getResponseCode();
            if(responseCode==200){
                String s = streamTostring(urlConnection.getInputStream());
                return s;
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    public String streamTostring(InputStream inputStream) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
        StringBuilder builder=new StringBuilder();
        for (String tmp=bufferedReader.readLine();tmp!=null;tmp=bufferedReader.readLine()){
            builder.append(tmp);
        }
        return builder.toString();
	    }
	}