封装HttpURLConnection

package com.pingyijinren.test;

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

/**
 * Created by Administrator on 2016/5/19 0019.
 */
public class HttpUtil {
    public interface HttpCallbackListener{
        void onFinish(String response);
        void onError(Exception e);
    }

    public static void sendHttpRequest(final String address,final HttpCallbackListener listener){  //子线程中无法返回数据，所以要使用接口
        new Thread(new Runnable() {
            @Override
            public void run() {
                HttpURLConnection connection=null;
                try{
                    URL url=new URL(address);
                    connection=(HttpURLConnection)url.openConnection();
                    connection.setRequestMethod("GET");
                    connection.setConnectTimeout(8000);
                    connection.setReadTimeout(8000);
                    connection.setDoInput(true);
                    connection.setDoOutput(true);
                    InputStream in=connection.getInputStream();
                    BufferedReader reader=new BufferedReader(new InputStreamReader(in));
                    StringBuilder response=new StringBuilder();
                    String line;
                    while((line=reader.readLine())!=null){
                        response.append(line);
                    }
                    if(listener!=null){
                        listener.onFinish(response.toString());
                    }
                }
                catch(Exception e){
                    if(listener!=null){
                        listener.onError(e);
                    }
                }
                finally {
                    if(connection!=null){
                        connection.disconnect();
                    }
                }
            }
        }).start();
    }
}

package com.pingyijinren.test;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity{
    private Button button;

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

        button=(Button)findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String address="http://www.runoob.com";
                HttpUtil.sendHttpRequest(address, new HttpUtil.HttpCallbackListener() {
                    @Override
                    public void onFinish(String response) {
                        Log.d("MainActivity",response);  //更新UI还是要使用异步消息处理机制
                    }

                    @Override
                    public void onError(Exception e) {
                        e.printStackTrace();
                        Log.d("MainActivity",e.getMessage());
                    }
                });
            }
        });
    }
}