Question

求java即时通讯的一个简单功能代码

最近在学习java网络编程，现在想写一个小功能：
要求是：一个服务器端，每个客户端必须登录，然后登陆后从服务器获取其它客户端的IP和端口，然后客户端于客户端直接进行通讯，不需要再经过服务器端，这个功能应该怎么实现呢？最好是有代码，先谢谢各位了！

Answer 1

20分！！！？？(⊙o⊙)
给你这个做参考吧。自己改一下就行了。（共两个文件）
//ChatClient.java
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;

public class ChatClient extends Frame {
Socket s = null;
DataOutputStream dos = null;
DataInputStream dis = null;
private boolean bConnected = false;

TextField tfTxt = new TextField();

TextArea taContent = new TextArea();

Thread tRecv = new Thread(new RecvThread());

public static void main(String[] args) {
new ChatClient().launchFrame();
}

public void launchFrame() {
setLocation(400, 300);
this.setSize(300, 300);
add(tfTxt, BorderLayout.SOUTH);
add(taContent, BorderLayout.NORTH);
pack();
this.addWindowListener(new WindowAdapter() {

@Override
public void windowClosing(WindowEvent arg0) {
disconnect();
System.exit(0);
}

});
tfTxt.addActionListener(new TFListener());
setVisible(true);
connect();

tRecv.start();
}

public void connect() {
try {
s = new Socket("127.0.0.1", 8888);
dos = new DataOutputStream(s.getOutputStream());
dis = new DataInputStream(s.getInputStream());
System.out.println("connected!");
bConnected = true;
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}

}

public void disconnect() {
try {
dos.close();
dis.close();
s.close();
} catch (IOException e) {
e.printStackTrace();
}

/*
try {
bConnected = false;
tRecv.join();
} catch(InterruptedException e) {
e.printStackTrace();
} finally {
try {
dos.close();
dis.close();
s.close();
} catch (IOException e) {
e.printStackTrace();
}
}
*/
}

private class TFListener implements ActionListener {

public void actionPerformed(ActionEvent e) {
String str = tfTxt.getText().trim();
//taContent.setText(str);
tfTxt.setText("");

try {
//System.out.println(s);
dos.writeUTF(str);
dos.flush();
//dos.close();
} catch (IOException e1) {
e1.printStackTrace();
}

}

}

private class RecvThread implements Runnable {

public void run() {
try {
while(bConnected) {
String str = dis.readUTF();
//System.out.println(str);
taContent.setText(taContent.getText() + str + '\n');
}
} catch (SocketException e) {
System.out.println("退出了，bye!");
} catch (EOFException e) {
System.out.println("推出了，bye - bye!");
} catch (IOException e) {
e.printStackTrace();
}

}

}
}
//ChatServer.java
import java.io.*;
import java.net.*;
import java.util.*;

public class ChatServer {
boolean started = false;
ServerSocket ss = null;

List<Client> clients = new ArrayList<Client>();

public static void main(String[] args) {
new ChatServer().start();
}

public void start() {
try {
ss = new ServerSocket(8888);
started = true;
} catch (BindException e) {
System.out.println("端口使用中....");
System.out.println("请关掉相关程序并重新运行服务器！");
System.exit(0);
} catch (IOException e) {
e.printStackTrace();
}

try {

while(started) {
Socket s = ss.accept();
Client c = new Client(s);
System.out.println("a client connected!");
new Thread(c).start();
clients.add(c);
//dis.close();
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
ss.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

class Client implements Runnable {
private Socket s;
private DataInputStream dis = null;
private DataOutputStream dos = null;
private boolean bConnected = false;

public Client(Socket s) {
this.s = s;
try {
dis = new DataInputStream(s.getInputStream());
dos = new DataOutputStream(s.getOutputStream());
bConnected = true;
} catch (IOException e) {
e.printStackTrace();
}
}

public void send(String str) {
try {
dos.writeUTF(str);
} catch (IOException e) {
clients.remove(this);
System.out.println("对方退出了！我从List里面去掉了！");
//e.printStackTrace();
}
}

public void run() {
try {
while(bConnected) {
String str = dis.readUTF();
System.out.println(str);
for(int i=0; i<clients.size(); i++) {
Client c = clients.get(i);
c.send(str);
//System.out.println(" a string send !");
}
/*
for(Iterator<Client> it = clients.iterator(); it.hasNext(); ) {
Client c = it.next();
c.send(str);
}
*/
/*
Iterator<Client> it = clients.iterator();
while(it.hasNext()) {
Client c = it.next();
c.send(str);
}
*/
}
} catch (EOFException e) {
System.out.println("Client closed!");
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if(dis != null) dis.close();
if(dos != null) dos.close();
if(s != null) {
s.close();
//s = null;
}

} catch (IOException e1) {
e1.printStackTrace();
}

}
}

}
}