详细讲解Android的网络通信（HttpUrlConnection和HttpClient）

前言，Android的网络通信的方式有两种：使用Socket或者HTTP，今天这一篇我们详细讲解使用HTTP实现的网络通信，HTTP又包括两种方式编程方式：

（1）HttpUrlConnection；

（2）HttpClient；

   好了，我们直接进行讲解，当然之前也会有一部分有关Android网络通信的其他知识，我们也应该了解。

 

一.获取网络状态的方法

（1）MainActivity.java中的关键代码

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//网络管理类，可以判断是否能上网，以及网络类型             ConnectivityManager cm=(ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);             NetworkInfo info=cm.getActiveNetworkInfo();             if(info!=null){                 Toast.makeText(MainActivity.this, "连网正常"+info.getTypeName(), Toast.LENGTH_SHORT).show();             }else{                 Toast.makeText(MainActivity.this, "未连网", Toast.LENGTH_SHORT).show();             }

（2）注意：一定要在主配置文件中增加这个权限

   它是application的兄弟标签：

1	<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

（3）OK，我们看一下我们的设备的上网状态和类型吧：

 

二.使用URL访问网页源码

（1）MainActivity.java：

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package com.example.l0903_urldata; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.net.MalformedURLException; import java.net.URL; import android.app.Activity; import android.os.Bundle; /**  * 访问网页源码  * @author asus  *  */ public class MainActivity extends Activity {     @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);         try {             //访问百度的html文件的源码             InputStream is=new URL("http://www.baidu.com").openStream();             //读取数据的包装流             BufferedReader br=new BufferedReader(new InputStreamReader(is));             //str用于读取一行数据             String str=null;             //StringBuffer用于存储所欲数据             StringBuffer sb=new StringBuffer();             while((str=br.readLine())!=null){                 sb.append(str);             }             System.out.println(sb.toString());         } catch (MalformedURLException e) {             e.printStackTrace();         } catch (IOException e) {             e.printStackTrace();         }     } }

（2）注意：有关网络的操作都需要在主配置文件里添加下面这个权限：

1	<uses-permission android:name="android.permission.INTERNET"/>

 

三.WebView 控件的简单使用

   

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package com.example.l0903_webview; import android.app.Activity; import android.os.Bundle; import android.webkit.WebView; /**  * 就是一个浏览器控件  * 其实没什么用  * @author asus  *  */ public class MainActivity extends Activity {     private WebView wv;     @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);         wv=(WebView) findViewById(R.id.webView1);         //WebView控件的方法，loadUrl用于加载指定的网络地址         wv.loadUrl("http://www.baidu.com");     } }

   运行效果：

 

四.使用HttpUrlConnection的编写方式实现Android的网络通信

1.首先，自己先搭建一个服务器：

 

 

2.下面是客户端的事了：

(1)通过get方式：

   MainActivity.java：

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package com.example.l0903_httpurlcnectionget; 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 android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.EditText; import android.widget.TextView; /**  * 通过Get方法获取服务器的数据  * 直接在地址中用"?+键值+value"的方式来使用  * 所以传递的参数直接显示出来，不安全  * @author asus  *  */ public class MainActivity extends Activity {     private HttpURLConnection conn;     private URL url;     private InputStream is;     private TextView tv;     private EditText et;     private String name;     @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);         tv=(TextView) findViewById(R.id.textView1);         et=(EditText) findViewById(R.id.editText1);         findViewById(R.id.button1).setOnClickListener(new OnClickListener() {                                                                                                                                                            @Override             public void onClick(View v) {                 name=et.getText().toString();                 //定义访问的服务器地址，10.0.2.2是Android的访问的本地服务器地址                 String urlDate="http://10.0.2.2:8080/My_Service/webdate.jsp?name="+name;                 try {                     //封装访问服务器的地址                     url=new URL(urlDate);                     try {                         //打开对服务器的连接                         conn=(HttpURLConnection) url.openConnection();                         //连接服务器                         conn.connect();                         /**读入服务器数据的过程**/                         //得到输入流                         is=conn.getInputStream();                         //创建包装流                         BufferedReader br=new BufferedReader(new InputStreamReader(is));                         //定义String类型用于储存单行数据                         String line=null;                         //创建StringBuffer对象用于存储所有数据                         StringBuffer sb=new StringBuffer();                         while((line=br.readLine())!=null){                             sb.append(line);                         }                         //用TextView显示接收的服务器数据                         tv.setText(sb.toString());                         System.out.println(sb.toString());                     } catch (IOException e) {                         e.printStackTrace();                     }                 } catch (MalformedURLException e) {                     e.printStackTrace();                 }             }         });     } }

   权限（同上面第二个，所有与网络有关的操作都需要添加，下面的就不再赘述了）

   运行效果：

 

（2）通过post方式（安全）

MainActivity.java

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package com.example.l0903_httpurlconectionpost; import java.io.BufferedReader; import java.io.DataOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStream; import java.net.HttpURLConnection; import java.net.MalformedURLException; import java.net.URL; import java.net.URLEncoder; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.EditText; import android.widget.TextView; /**  * 通过Post方法传递参数  * 安全  * @author asus  *  */ public class MainActivity extends Activity {     private HttpURLConnection conn;     private URL url;     private InputStream is;     private OutputStream os;     private EditText et;     private TextView tv;     @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);         et=(EditText) findViewById(R.id.editText1);         tv=(TextView) findViewById(R.id.tv);         findViewById(R.id.button1).setOnClickListener(new OnClickListener() {                                                                                                 @Override             public void onClick(View v) {                 // TODO Auto-generated method stub                 String urlDate="http://10.0.2.2:8080/My_Service/webdate.jsp";                 try {                     url=new URL(urlDate);                     try {                         //打开服务器                         conn=(HttpURLConnection) url.openConnection();                         //设置输入输出流                         conn.setDoOutput(true);                         conn.setDoInput(true);                         //设置请求的方法为Post                         conn.setRequestMethod("POST");                         //Post方式不能缓存数据，则需要手动设置使用缓存的值为false                         conn.setUseCaches(false);                         //连接数据库                         conn.connect();                         /**写入参数**/                         os=conn.getOutputStream();                         //封装写给服务器的数据（这里是要传递的参数）                         DataOutputStream dos=new DataOutputStream(os);                         //写方法：name是key值不能变，编码方式使用UTF-8可以用中文                         dos.writeBytes("name="+URLEncoder.encode(et.getText().toString(), "UTF-8"));                         //关闭外包装流                         dos.close();                         /**读服务器数据**/                         is=conn.getInputStream();                         BufferedReader br=new BufferedReader(new InputStreamReader(is));                         String line=null;                         StringBuffer sb=new StringBuffer();                         while((line=br.readLine())!=null){                             sb.append(line);                         }                         tv.setText(sb.toString());                         System.out.println(sb.toString());                     } catch (IOException e) {                         e.printStackTrace();                     }                 } catch (MalformedURLException e) {                     e.printStackTrace();                 }             }         });                                                                                 } }

 

 

五.使用HttpClient的编写方式实现Android的网络通信

1.服务器同上；

2.使用get的方式：

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package com.example.l0903_http_get; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpGet; import org.apache.http.impl.client.DefaultHttpClient; import android.app.Activity; import android.os.Bundle; public class MainActivity extends Activity {     private HttpGet get;     private HttpClient cliet;     private HttpResponse response;     private HttpEntity entity;     private InputStream is;     @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);         get=new HttpGet("http://10.0.2.2:8080/My_Service/webdate.jsp?name=ooooooo");         cliet=new DefaultHttpClient();         try {             response=cliet.execute(get);             entity=response.getEntity();             is=entity.getContent();             BufferedReader br=new BufferedReader(new InputStreamReader(is));             String line=null;             StringBuffer sb=new StringBuffer();             while((line=br.readLine())!=null){                 sb.append(line);             }             System.out.println(sb.toString());         } catch (ClientProtocolException e) {             e.printStackTrace();         } catch (IOException e) {             e.printStackTrace();         }                                                      } }

 

3.使用post的方式：

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package com.example.l0903_http_post; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.UnsupportedEncodingException; import java.util.ArrayList; import java.util.List; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.HttpClient; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.HttpPost; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.message.BasicNameValuePair; import android.app.Activity; import android.os.Bundle; public class MainActivity extends Activity {     //创建请求对象     private HttpPost post;     //创建客户端对象     private HttpClient cliet;     //创建发送请求的对象     private HttpResponse response;     //     private UrlEncodedFormEntity urlEntity;     //创建接收返回数据的对象     private HttpEntity entity;     //创建流对象     private InputStream is;     @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);         //包装请求的地址         post=new HttpPost("http://10.0.2.2:8080/My_Service/webdate.jsp");         //创建默认的客户端对象         cliet=new DefaultHttpClient();         //用list封装要向服务器端发送的参数         List<BasicNameValuePair> pairs=new ArrayList<BasicNameValuePair>();         pairs.add(new BasicNameValuePair("name", "llllllllll"));         try {             //用UrlEncodedFormEntity来封装List对象             urlEntity=new UrlEncodedFormEntity(pairs);             //设置使用的Entity             post.setEntity(urlEntity);             try {                 //客户端开始向指定的网址发送请求                 response=cliet.execute(post);                 //获得请求的Entity                 entity=response.getEntity();                 is=entity.getContent();                 //下面是读取数据的过程                 BufferedReader br=new BufferedReader(new InputStreamReader(is));                 String line=null;                 StringBuffer sb=new StringBuffer();                 while((line=br.readLine())!=null){                     sb.append(line);                 }                 System.out.println(sb.toString());             } catch (ClientProtocolException e) {                 e.printStackTrace();             } catch (IOException e) {                 e.printStackTrace();             }         } catch (UnsupportedEncodingException e) {             e.printStackTrace();         }                                                                                                 } }

 

4.实现HttpClient通信与AsyncTask异步机制的结合：

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package com.example.l0903_http_asynctask_get; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpGet; import org.apache.http.impl.client.DefaultHttpClient; import android.app.Activity; import android.app.ProgressDialog; import android.os.AsyncTask; import android.os.Bundle; import android.widget.TextView; /**  *  * @author asus  *  */ public class MainActivity extends Activity {     private TextView tv;// 创建请求对象     private HttpGet httpGet;     // 创建客户端对象     private HttpClient httpClient;     // 发送请求的对象     private HttpResponse httpResponse;     // 接收返回数据     private HttpEntity httpEntity;     // 创建流     private InputStream in;     private ProgressDialog pd;     @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);         tv = (TextView) findViewById(R.id.tv);         AsyncTask<String, Void, String> asyncTask = new AsyncTask<String, Void, String>() {             @Override             protected String doInString...  params) {                 String urlstr = params[0];                 httpGet = new HttpGet(urlstr);                 httpClient = new DefaultHttpClient();                 try {                     // 向服务器端发送请求                     httpResponse = httpClient.execute(httpGet);                     httpEntity = httpResponse.getEntity();                     in = httpEntity.getContent();                     BufferedReader br = new BufferedReader(                             new InputStreamReader(in));                     String line = null;                     StringBuffer sb = new StringBuffer();                     while ((line = br.readLine()) != null) {                         sb.append(line);                     }                     System.out.println(sb.toString());                     return sb.toString();                 } catch (ClientProtocolException e) {                     e.printStackTrace();                 } catch (IOException e) {                     e.printStackTrace();                 }                 return null;             }             @Override             protected void onPostExecute(String result) {                 if (result != null) {                     tv.setText(result);                     pd.dismiss();// 消除dialog                 }                 super.onPostExecute(result);             }         };         pd = ProgressDialog.show(this, "请稍后。。。", "正在请求数据");         asyncTask.execute("http://10.0.2.2:8080/My_Service/webdate.jsp?name=haha&age=hh");     } }

运行效果：