使用OkHttp

        OkHttp是鼎鼎大名的Square公司开发的，这个公司在开源事业上面贡献良多，除了OkHttp之外，还开发了像Picasso、Retrofit等著名的开源项目。OkHttp不仅在接口封装上面做的简单易用，就连在底层实现上也是自成一派，比起原生的HttpURLConnection，可以说是有过之而无不及，现在已经成了广大Android开发者首选的网络通信库

一、在使用OkHttp之前，我们需要先在项目中添加OkHttp库的依赖，编辑app/buils.gradle文件，在dependencies闭包中添加如下内容：

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.squareup.okhttp3:okhttp:3.2.0'         //添加这行程序
}

二、布局文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">



    <Button
        android:id="@+id/sendRequest"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Send Request"/>
    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <TextView
            android:id="@+id/responseText"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />
    </ScrollView>

</RelativeLayout>

三、直接修改MainActivity中的代码

package com.example.yxp.httplcc;

import android.app.Activity;
import android.app.DownloadManager;
import android.app.VoiceInteractor;
import android.os.Bundle;
import android.os.Message;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.os.Handler;


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

import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class MainActivity extends Activity  {

    public static final int SHOW_RESPONSE=0;//用于更新操作
    private Button sendRequest;
    private TextView responseText;



    //用于处理和发送消息的Hander
    private Handler handler=new Handler(){
        public void handleMessage(Message msg){
            //如果返现msg.what=SHOW_RESPONSE，则进行制定操作，如想进行其他操作，则在子线程里将SHOW_RESPONSE改变
            switch (msg.what){
                case SHOW_RESPONSE:
                    String response=(String)msg.obj;
                    //进行UI操作，将结果显示到界面上
                    responseText.setText(response);
            }
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        sendRequest=(Button)findViewById(R.id.sendRequest);
        responseText=(TextView)findViewById(R.id.responseText);
        sendRequest.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

               // sendRequestWithHttpURLConnection();
                sendRequestwithOkHttp();



            }
        });
    }



    private void  sendRequestwithOkHttp(){
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    OkHttpClient client = new OkHttpClient();
                    Request request = new Request.Builder().url("http://www.baidu.com").build();
                    Response response = client.newCall(request).execute();
                    String responseData = response.body().string();
                    showResponse(responseData);
                } catch (IOException e) {
                    e.printStackTrace();
                }

            }


        }).start();
    }




    private void sendRequestWithHttpURLConnection(){
        //开启线程来发起网络请求
        new Thread(new Runnable() {
            @Override
            public void run() {
                HttpURLConnection connection=null;
                try{
                    URL url=new URL("https://www.cnblogs.com/Liang-Blog/p/5760201.html");
                    connection=(HttpURLConnection)url.openConnection();
                    connection.setRequestMethod("GET");
                    connection.setConnectTimeout(8000);
                    connection.setReadTimeout(8000);

                    InputStream in=connection.getInputStream();
                    //下面对获取到的输入流进行读取
                    BufferedReader bufr=new BufferedReader(new InputStreamReader(in));
                    StringBuilder response=new StringBuilder();
                    String line=null;
                    while((line=bufr.readLine())!=null){
                        response.append(line);
                    }

                    Message message=new Message();
                    message.what=SHOW_RESPONSE;
                    //将服务器返回的数据存放到Message中
                    message.obj=response.toString();
                    handler.sendMessage(message);
                }catch(Exception e){
                    e.printStackTrace();
                }finally {
                    if(connection!=null){
                        connection.disconnect();
                    }
                }
            }
        }).start();
    }



    private void showResponse(final String response){
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                responseText.setText(response);

            }
        });
    }

}

实现效果