多向通信----多人聊天

package 多人聊天;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
public class Gserver implements Runnable {
   private int Port = 9999;
   private ServerSocket SS;
   private Socket socket;
   private ArrayList clients = new ArrayList(); //保存客户端线程
   public Gserver(){
       try{
           SS = new ServerSocket(Port);
           new Thread(this).start();
       }catch(Exception ex){
       }
   }
   public void run(){
       try{
           while(true){
               socket = SS.accept();
               ChatThread ct = new ChatThread(socket);
               clients.add(ct);
               ct.start();
           }
       }catch(Exception ex){
       }
   }
   class ChatThread extends Thread{
       private Socket s;
       private InputStream is;
       private OutputStream os;
       private BufferedReader br;
       private PrintStream ps;
       public ChatThread(Socket socket) throws Exception{
           this.s = socket;
           is = this.s.getInputStream();
           os = this.s.getOutputStream();
           br = new BufferedReader(new InputStreamReader(is));
           ps = new PrintStream(os);
       }
       public void run(){
           try{
               while(true){
                   String str = br.readLine();
                   sendMessage(str);
               }
           }catch (Exception ex){
           }
       }
       public void sendMessage(String str){
           for(int i=0; i<clients.size(); i++){
               ChatThread ct = (ChatThread)clients.get(i);
               ct.ps.println(str);
           }
       }
   }
   public static void main(String[] args){
       new Gserver();
   }
}

客户端

package 多人聊天;

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintStream;
import java.net.InetAddress;
import java.net.Socket;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
public class Gclient extends JFrame implements ActionListener, Runnable {
   private Socket socket;
   private int Port = 9999;
   private InetAddress ip;
   private String name;

   private JTextArea area = new JTextArea("以下是聊天内容：\n");
   private JTextField field = new JTextField("");

   public Gclient(){
       this.setTitle("客户端");
       this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       this.add(field,BorderLayout.NORTH);
       field.addActionListener(this);
       this.add(area, BorderLayout.CENTER);
       this.setSize(240, 260);
       this.setVisible(true);
       name = JOptionPane.showInputDialog("输入昵称：");
       try{
           ip = InetAddress.getByName("Localhost");
           socket = new Socket(ip,Port);
           JOptionPane.showMessageDialog(this, "连接成功");
           this.setTitle("客户端：" + name);
           new Thread(this).start();
       }catch (Exception ex){
       }
   }
   public void run(){
       try{
           while(true){
               InputStream is = socket.getInputStream();
               BufferedReader bf = new BufferedReader(new InputStreamReader(is));
               String str = bf.readLine();
               area.append(str + '\n');
           }
       }catch (Exception ex){
       }
   }
   public void actionPerformed(ActionEvent e){
       try{
           OutputStream os = socket.getOutputStream();
           PrintStream ps = new PrintStream(os);
           ps.println(name + "说：" + field.getText());
           field.setText("");
       }catch (Exception ex){
       }
   }
   public static void main(String[] args) {
       new Gclient();
   }
}