Java写的P2P聊天程序

这几天偶然想研究下P2P通信的原理，于是就用Java写了一个，测试可以通过，但是在不同的运营商之间却有点问题，比如联通跟电信之间可能出现不通现象，不知是不是被卡杀了。

客户端：

Java代码

 

1. import java.awt.BorderLayout;  
2. import java.awt.event.ActionEvent;  
3. import java.awt.event.ActionListener;  
4. import java.awt.event.WindowAdapter;  
5. import java.awt.event.WindowEvent;  
6. import java.io.BufferedReader;  
7. import java.io.FileInputStream;  
8. import java.io.InputStreamReader;  
9. import java.net.DatagramPacket;  
10. import java.net.DatagramSocket;  
11. import java.net.InetSocketAddress;  
12. import java.net.SocketAddress;  
13. import java.util.ArrayList;  
14. import java.util.HashMap;  
15. import java.util.List;  
16. import java.util.Map;  
17. import java.util.Map.Entry;  
18. import java.util.Set;  
19.   
20. import javax.swing.JButton;  
21. import javax.swing.JFrame;  
22. import javax.swing.JLabel;  
23. import javax.swing.JPanel;  
24. import javax.swing.JScrollBar;  
25. import javax.swing.JTextArea;  
26. import javax.swing.JTextField;  
27.   
28. public class Client extends Thread implements ActionListener{  
29.     //是否停止  
30.     public static int STOP=0;  
31.       
32.     //在线用户列表  
33.     public static Map userMap=new HashMap();  
34.       
35.     private DatagramSocket client;  
36.       
37.     private JFrame frame;  
38.     //聊天信息  
39.     private JTextArea info;  
40.     //在线用户  
41.     private JTextArea onlineUser;  
42.     private JTextField msgText;  
43.       
44.     private JButton sendButton;  
45.       
46.     public Client(DatagramSocket client)throws Exception  
47.     {  
48.   
49.         this.client=client;  
50.         this.frame=new JFrame("P2P聊天");  
51.         frame.setSize(800, 400);  
52.           
53.         sendButton=new JButton("发送");  
54.         JScrollBar scroll=new JScrollBar();  
55.         this.info=new JTextArea(10,30);  
56.         //激活自动换行功能   
57.         info.setLineWrap(true);  
58.         info.setWrapStyleWord(true);  
59.         info.setEditable(false);  
60.         scroll.add(info);  
61.           
62.         onlineUser=new JTextArea(10,30);  
63.         onlineUser.setLineWrap(true);  
64.         onlineUser.setWrapStyleWord(true);  
65.         onlineUser.setEditable(false);  
66.           
67.           
68.         JPanel infopanel=new JPanel();  
69.         infopanel.add(info,BorderLayout.WEST);  
70.         JPanel infopanel1=new JPanel();  
71.         JLabel label=new JLabel("在线用户");  
72.         infopanel1.add(label, BorderLayout.NORTH);  
73.         infopanel1.add(onlineUser, BorderLayout.SOUTH);  
74.         infopanel.add(infopanel1,BorderLayout.EAST);  
75.   
76.         JPanel panel=new JPanel();  
77.           
78.         msgText=new JTextField(30);  
79.       
80.         panel.add(msgText);  
81.         panel.add(sendButton);  
82.         frame.add(infopanel,BorderLayout.NORTH);  
83.         frame.add(panel,BorderLayout.SOUTH);  
84.         frame.setVisible(true);  
85.           
86.         sendButton.addActionListener(this);  
87.           
88.         frame.addWindowListener(new   WindowAdapter(){   
89.             public   void   windowClosing(WindowEvent   e){   
90.                 System.exit(0);  
91.             }   
92.          });   
93.           
94.   
95.     }  
96.       
97.     /** 
98.      * 给其他在线用户发送心跳 保持session有效 
99.      */  
100.     private void sendSkip()  
101.     {  
102.         new Thread(){  
103.             public void run()  
104.             {  
105.                 try  
106.                 {  
107.                     String msg="skip";  
108.                     while(true)  
109.                     {  
110.                         if(STOP==1)  
111.                             break;  
112.                         if(userMap.size()>0)  
113.                         {  
114.                              for (Entry entry : userMap.entrySet()) {  
115.                                  DatagramPacket data=new DatagramPacket(msg.getBytes(),msg.getBytes().length,entry.getValue());  
116.                                 client.send(data);  
117.                             }  
118.                         }  
119.                         //每10s发送一次心跳  
120.                         Thread.sleep(10*1000);  
121.                     }  
122.                 }catch(Exception e){}  
123.                   
124.             }  
125.         }.start();  
126.     }  
127.       
128.     //主要任务是接收数据  
129.     //可以是其他用户发来的信息，也可以是服务器发来的在线用户数据  
130.     public void run()  
131.     {  
132.         try  
133.         {  
134.               
135.             String msg;  
136.             DatagramPacket data;  
137.               
138.             //执行心跳  
139.             sendSkip();  
140.               
141.             while(true)  
142.             {  
143.                 if(STOP==1)  
144.                     break;  
145.                 byte[] buf=new byte[1024];  
146.                 DatagramPacket packet = new DatagramPacket(buf, buf.length);  
147.                 client.receive(packet);  
148.                 msg=new String(packet.getData(),0,packet.getLength());  
149.                 if(msg.length()>0)  
150.                 {  
151.                     if(msg.indexOf("server:")>-1)  
152.                     {  
153.                         //服务器数据 格式server:ID#IP：PORT，。。  
154.                         String userdata=msg.substring(msg.indexOf(":")+1,msg.length());  
155.                         String[] user=userdata.split(",");  
156.                         for(String u:user)  
157.                         {  
158.                             if(u!=null&&u.length()>0)  
159.                             {  
160.                                 String[] udata=u.split("#");  
161.                                 String ip=udata[1].split(":")[0];  
162.                                 int port=Integer.parseInt(udata[1].split(":")[1]);  
163.                                   
164.                                 ip=ip.substring(1,ip.length());  
165.                                   
166.                                 SocketAddress adds=new InetSocketAddress(ip,port);  
167.                                 userMap.put(udata[0], adds);  
168.                                 //给对方打洞 发送空白报文  
169.                                 data=new DatagramPacket(new byte[0],0,adds);  
170.                                 client.send(data);  
171.                                   
172.                             }  
173.                               
174.                         }  
175.                         //更新在线用户列表  
176.                         this.onlineUser.setText("");  
177.                         for (Map.Entry entry : userMap.entrySet()) {  
178.                             this.onlineUser.append("用户"+entry.getKey()+"("+entry.getValue()+")\n");  
179.                         }  
180.   
181.                     }  
182.                     else if(msg.indexOf("skip")>-1);  
183.                     else  
184.                     {  
185.                         //普通消息  
186.                         this.info.append(packet.getAddress().toString()+packet.getPort()+" 说："+msg);  
187.                         this.info.append("\n");  
188.                     }  
189.                 }  
190.             }  
191.         }  
192.         catch(Exception e){}  
193.     }  
194.       
195.     public static void main(String args[])throws Exception  
196.     {  
197.           
198.         String serverIP="122.225.99.40";///122.225.99.40  
199.         int port=6636;  
200.           
201.         //构造一个目标地址  
202.         SocketAddress target = new InetSocketAddress(serverIP, port);   
203.           
204.         DatagramSocket client = new DatagramSocket();  
205.         String msg="向服务器报告！";  
206.         byte[] buf=msg.getBytes();  
207.         //向服务器发送上线数据  
208.         DatagramPacket packet=new DatagramPacket(buf,buf.length,target);  
209.         client.send(packet);  
210.         new Client(client).start();  
211.           
212.     }  
213.   
214.       
215.     //按钮事件  
216.     @Override  
217.     public void actionPerformed(ActionEvent e) {  
218.         if(e.getSource()==this.sendButton)  
219.         {  
220.             try{  
221.                 String msg=this.msgText.getText();  
222.                 if(msg.length()>0)  
223.                 {  
224.                     this.info.append("我说："+msg);  
225.                     this.info.append("\n");  
226.                     for (Map.Entry entry : userMap.entrySet()) {  
227.                         DatagramPacket data=new DatagramPacket(msg.getBytes(),msg.getBytes().length,entry.getValue());  
228.                         client.send(data);  
229.                     }  
230.                       
231.                     this.msgText.setText("");  
232.                 }  
233.             }  
234.             catch(Exception ee){}  
235.         }  
236.           
237.     }  
238. }  

 服务器端：

Java代码  

1. import java.io.BufferedReader;  
2. import java.io.BufferedWriter;  
3. import java.io.IOException;  
4. import java.io.InputStreamReader;  
5. import java.io.OutputStreamWriter;  
6. import java.io.PrintWriter;  
7. import java.net.DatagramPacket;  
8. import java.net.DatagramSocket;  
9. import java.net.InetAddress;  
10. import java.net.ServerSocket;  
11. import java.net.Socket;  
12. import java.util.ArrayList;  
13. import java.util.HashMap;  
14. import java.util.List;  
15. import java.util.Map;  
16.   
17. /** 
18.  * 服务端 
19.  * @author ggxin 
20.  * 
21.  */  
22. public class Server extends Thread{  
23.     //存储所有的用户IP与端口  
24.     public static List
25.     //在线用户IP  
26.     public static Map users=new HashMap();  
27.       
28.     public static int index=1;  
29.       
30.     private DatagramSocket server;  
31.       
32.     public Server(DatagramSocket server)  
33.     {  
34.         this.server=server;  
35.     }  
36.     //线程负责给在线用户发送当前所有在线用户的信息  
37.     public void run()  
38.     {  
39.         try  
40.         {  
41.             DatagramPacket sendPacket;  
42.             StringBuffer msg;  
43.             while(true)  
44.             {  
45.                 for(Map user:Server.userList)  
46.                 {  
47.                     //服务器数据，标记server:  
48.                     msg=new StringBuffer("server:");  
49.                     for(Map map:Server.userList)  
50.                     {  
51.                         if(!map.get("id").toString().equals(user.get("id").toString()))  
52.                         {  
53.                             msg.append(map.get("id")+"#"+map.get("ip")+":"+map.get("port"));  
54.                             msg.append(",");  
55.                         }  
56.                     }  
57.                     if(!msg.toString().equals("server:"))  
58.                     {  
59.                         byte[] data=msg.toString().getBytes();  
60.                         //构造发送报文  
61.                         sendPacket = new DatagramPacket(data, data.length, (InetAddress)user.get("ip"), (Integer)user.get("port"));    
62.                         server.send(sendPacket);  
63.                     }  
64.                 }  
65.                 Thread.sleep(2000);  
66.                   
67.             }  
68.         }catch(Exception e){}  
69.     }  
70.       
71.       
72.     public static void main(String args[])throws Exception  
73.     {  
74.   
75.         int port=6636;  
76.           
77.         //创建一个UDPsocket  
78.         DatagramSocket server = new DatagramSocket(port);  
79.         byte[] buf = new byte[1024];    
80.         //接收数据的udp包  
81.         DatagramPacket packet = new DatagramPacket(buf, buf.length);  
82.          
83.         //开启服务  
84.         new Server(server).start();  
85.   
86.         String msg;  
87.         //循环接收数据  
88.         while(true)  
89.         {  
90.               
91.             server.receive(packet);  
92.               
93.             msg=new String(packet.getData(),0,packet.getLength());  
94.               
95.             if(msg!=null&&msg.equals("bye"))  
96.                 break;  
97.               
98.             if(msg.length()>0)  
99.             {  
100.                 System.out.println("收到数据来自：("+packet.getAddress()+":"+packet.getPort()+")="+msg);  
101.                 if(!users.containsKey(packet.getAddress()+":"+packet.getPort()))  
102.                 {  
103.                     Map map=new HashMap();  
104.                     map.put("id", index);  
105.                     map.put("ip", packet.getAddress());  
106.                     map.put("port", packet.getPort());  
107.                     userList.add(map);  
108.                       
109.                     users.put(packet.getAddress()+":"+packet.getPort(), index);  
110.                     index++;  
111.                 }  
112.                   
113.             }  
114.         }  
115.         server.close();  
116.     }  
117.   
118. }