【Android筆記】Android的三種網絡通訊方式

時間 2019-12-08

標籤 Android筆記 android 三種網絡通訊方式欄目 Android 简体版

原文原文鏈接

Android平臺有三種網絡接口可使用，他們分別是：java.net.*(標準Java接口)、Org.apache接口和Android.net.*(Android網絡接口)。下面分別介紹這些接口的功能和做用。html

1.標準Java接口
java.net.*提供與聯網有關的類，包括流、數據包套接字(socket)、Internet協議、常見Http處理等。好比：建立URL，以及URLConnection/HttpURLConnection對象、設置連接參數、連接到服務器、向服務器寫數據、從服務器讀取數據等通訊。這些在Java網絡編程中均有涉及，咱們看一個簡單的socket編程，實現服務器回發客戶端信息。
服務端：java

 1 public class Server implements Runnable{  
 2     @Override  
 3     public void run() {  
 4         Socket socket = null;  
 5         try {  
 6             ServerSocket server = new ServerSocket(18888);  
 7             //循環監聽客戶端連接請求  
 8             while(true){  
 9                 System.out.println("start...");  
10                 //接收請求  
11                 socket = server.accept();  
12                 System.out.println("accept...");  
13                 //接收客戶端消息  
14                 BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));  
15                 String message = in.readLine();  
16                 //發送消息，向客戶端  
17                 PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);  
18                 out.println("Server:" + message);  
19                 //關閉流  
20                 in.close();  
21                 out.close();  
22             }  
23         } catch (IOException e) {  
24             e.printStackTrace();  
25         }finally{  
26             if (null != socket){  
27                 try {  
28                     socket.close();  
29                 } catch (IOException e) {  
30                     e.printStackTrace();  
31                 }  
32             }  
33         }  
34           
35     }  
36     //啓動服務器  
37     public static void main(String[] args){  
38         Thread server = new Thread(new Server());  
39         server.start();  
40     }  
41 }

客戶端，MainActivityandroid

 1 public class MainActivity extends Activity {  
 2     private EditText editText;  
 3     private Button button;  
 4     /** Called when the activity is first created. */  
 5     @Override  
 6     public void onCreate(Bundle savedInstanceState) {  
 7         super.onCreate(savedInstanceState);  
 8         setContentView(R.layout.main);  
 9           
10         editText = (EditText)findViewById(R.id.editText1);  
11         button = (Button)findViewById(R.id.button1);  
12           
13         button.setOnClickListener(new OnClickListener() {  
14             @Override  
15             public void onClick(View v) {  
16                 Socket socket = null;  
17                 String message = editText.getText().toString()+ "\r\n" ;  
18                 try {  
19                     //建立客戶端socket,注意:不能用localhost或127.0.0.1，Android模擬器把本身做爲localhost  
20                     socket = new Socket("<span style="font-weight: bold;">10.0.2.2</span>",18888);  
21                     PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter  
22                             (socket.getOutputStream())),true);  
23                     //發送數據  
24                     out.println(message);  
25                       
26                     //接收數據  
27                     BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));  
28                     String msg = in.readLine();  
29                     if (null != msg){  
30                         editText.setText(msg);  
31                         System.out.println(msg);  
32                     }  
33                     else{  
34                         editText.setText("data error");  
35                     }  
36                     out.close();  
37                     in.close();  
38                 } catch (UnknownHostException e) {  
39                     e.printStackTrace();  
40                 } catch (IOException e) {  
41                     e.printStackTrace();  
42                 }  
43                 finally{  
44                     try {  
45                         if (null != socket){  
46                             socket.close();  
47                         }  
48                     } catch (IOException e) {  
49                         e.printStackTrace();  
50                     }  
51                 }  
52             }  
53         });  
54     }  
55 }

佈局文件：web

 1 <?xml version="1.0" encoding="utf-8"?>  
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  
 3     android:orientation="vertical" android:layout_width="fill_parent"  
 4     android:layout_height="fill_parent">  
 5     <TextView android:layout_width="fill_parent"  
 6         android:layout_height="wrap_content" android:text="@string/hello" />  
 7     <EditText android:layout_width="match_parent" android:id="@+id/editText1"  
 8         android:layout_height="wrap_content"  
 9         android:hint="input the message and click the send button"  
10         ></EditText>  
11     <Button android:text="send" android:id="@+id/button1"  
12         android:layout_width="fill_parent" android:layout_height="wrap_content"></Button>  
13 </LinearLayout>

啓動服務器：apache

1 javac com/test/socket/Server.java  
2 java com.test.socket.Server

運行客戶端程序：編程

結果如圖：服務器

注意：服務器與客戶端沒法連接的可能緣由有：
沒有加訪問網絡的權限：<uses-permission android:name="android.permission.INTERNET"></uses-permission>
IP地址要使用：10.0.2.2
模擬器不能配置代理。網絡

2。Apache接口app

對於大部分應用程序而言JDK自己提供的網絡功能已遠遠不夠，這時就須要Android提供的Apache HttpClient了。它是一個開源項目，功能更加完善，爲客戶端的Http編程提供高效、最新、功能豐富的工具包支持。
下面咱們以一個簡單例子來看看如何使用HttpClient在Android客戶端訪問Web。
首先，要在你的機器上搭建一個web應用myapp，只有很簡單的一個http.jsp
內容以下：socket

 1 <%@page language="java" import="java.util.*" pageEncoding="utf-8"%>  
 2 <html>  
 3 <head>  
 4 <title>  
 5 Http Test  
 6 </title>  
 7 </head>  
 8 <body>  
 9 <%  
10 String type = request.getParameter("parameter");  
11 String result = new String(type.getBytes("iso-8859-1"),"utf-8");  
12 out.println("<h1>" + result + "</h1>");  
13 %>  
14 </body>  
15 </html>

而後實現Android客戶端，分別以post、get方式去訪問myapp,代碼以下：
佈局文件：

 1 <?xml version="1.0" encoding="utf-8"?>  
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  
 3     android:orientation="vertical"  
 4     android:layout_width="fill_parent"  
 5     android:layout_height="fill_parent"  
 6     >  
 7 <TextView  
 8     android:gravity="center"  
 9     android:id="@+id/textView"    
10     android:layout_width="fill_parent"  
11     android:layout_height="wrap_content"  
12     android:text="@string/hello"  
13     />  
14 <Button android:text="get" android:id="@+id/get" android:layout_width="match_parent" android:layout_height="wrap_content"></Button>  
15 <Button android:text="post" android:id="@+id/post" android:layout_width="match_parent" android:layout_height="wrap_content"></Button>  
16 </LinearLayout>

資源文件：
strings.xml

1 <?xml version="1.0" encoding="utf-8"?>  
2 <resources>  
3     <string name="hello">經過按鈕選擇不一樣方式訪問網頁</string>  
4     <string name="app_name">Http Get</string>  
5 </resources>

主Activity:

  1 public class MainActivity extends Activity {  
  2     private TextView textView;  
  3     private Button get,post;  
  4     /** Called when the activity is first created. */  
  5     @Override  
  6     public void onCreate(Bundle savedInstanceState) {  
  7         super.onCreate(savedInstanceState);  
  8         setContentView(R.layout.main);  
  9           
 10         textView = (TextView)findViewById(R.id.textView);  
 11         get = (Button)findViewById(R.id.get);  
 12         post = (Button)findViewById(R.id.post);  
 13           
 14         //綁定按鈕監聽器  
 15         get.setOnClickListener(new OnClickListener() {  
 16             @Override  
 17             public void onClick(View v) {  
 18                 //注意：此處ip不能用127.0.0.1或localhost,Android模擬器已將它本身做爲了localhost  
 19                 String uri = "http://192.168.22.28:8080/myapp/http.jsp?parameter=以Get方式發送請求";  
 20                 textView.setText(get(uri));  
 21             }  
 22         });  
 23         //綁定按鈕監聽器  
 24         post.setOnClickListener(new OnClickListener() {  
 25             @Override  
 26             public void onClick(View v) {  
 27                 String uri = "http://192.168.22.28:8080/myapp/http.jsp";  
 28                 textView.setText(post(uri));  
 29             }  
 30         });  
 31     }  
 32     /** 
 33      * 以get方式發送請求，訪問web 
 34      * @param uri web地址 
 35      * @return 響應數據 
 36      */  
 37     private static String get(String uri){  
 38         BufferedReader reader = null;  
 39         StringBuffer sb = null;  
 40         String result = "";  
 41         HttpClient client = new DefaultHttpClient();  
 42         HttpGet request = new HttpGet(uri);  
 43         try {  
 44             //發送請求，獲得響應  
 45             HttpResponse response = client.execute(request);  
 46               
 47             //請求成功  
 48             if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK){  
 49                 reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));  
 50                 sb = new StringBuffer();  
 51                 String line = "";  
 52                 String NL = System.getProperty("line.separator");  
 53                 while((line = reader.readLine()) != null){  
 54                     sb.append(line);  
 55                 }  
 56             }  
 57         } catch (ClientProtocolException e) {  
 58             e.printStackTrace();  
 59         } catch (IOException e) {  
 60             e.printStackTrace();  
 61         }  
 62         finally{  
 63             try {  
 64                 if (null != reader){  
 65                     reader.close();  
 66                     reader = null;  
 67                 }  
 68             } catch (IOException e) {  
 69                 e.printStackTrace();  
 70             }  
 71         }  
 72         if (null != sb){  
 73             result =  sb.toString();  
 74         }  
 75         return result;  
 76     }  
 77     /** 
 78      * 以post方式發送請求，訪問web 
 79      * @param uri web地址 
 80      * @return 響應數據 
 81      */  
 82     private static String post(String uri){  
 83         BufferedReader reader = null;  
 84         StringBuffer sb = null;  
 85         String result = "";  
 86         HttpClient client = new DefaultHttpClient();  
 87         HttpPost request = new HttpPost(uri);  
 88           
 89         //保存要傳遞的參數  
 90         List<NameValuePair> params = new ArrayList<NameValuePair>();  
 91         //添加參數  
 92         params.add(new BasicNameValuePair("parameter","以Post方式發送請求"));  
 93           
 94         try {  
 95             //設置字符集  
 96             HttpEntity entity = new UrlEncodedFormEntity(params,"utf-8");  
 97             //請求對象  
 98             request.setEntity(entity);  
 99             //發送請求  
100             HttpResponse response = client.execute(request);  
101               
102             //請求成功  
103             if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK){  
104                 System.out.println("post success");  
105                 reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));  
106                 sb = new StringBuffer();  
107                 String line = "";  
108                 String NL = System.getProperty("line.separator");  
109                 while((line = reader.readLine()) != null){  
110                     sb.append(line);  
111                 }  
112             }  
113         } catch (ClientProtocolException e) {  
114             e.printStackTrace();  
115         } catch (IOException e) {  
116             e.printStackTrace();  
117         }  
118         finally{  
119             try {  
120                 //關閉流  
121                 if (null != reader){  
122                     reader.close();  
123                     reader = null;  
124                 }  
125             } catch (IOException e) {  
126                 e.printStackTrace();  
127             }  
128         }  
129         if (null != sb){  
130             result =  sb.toString();  
131         }  
132         return result;  
133     }  
134 }