网络编程之简单的多人聊天程序

服务器端

package net;
import java.awt.*;
import java.io.*;
import java.net.*;
import java.util.*;
import java.util.List;

import javax.swing.*;
//服务器端程序
public class TCPServer extends JFrame {
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private ServerSocket ss = null;
	private boolean bStart = false;
	
	private JTextArea taContent = new JTextArea();
	
	private int index = 0;
	
	List<Client> clients = new ArrayList<Client>();
	
	public void launchFrame() {
		//Container con = this.getContentPane();
		taContent.setEditable(false);
		taContent.setBackground(Color.DARK_GRAY);
		taContent.setForeground(Color.YELLOW);
		this.add(taContent);
		this.setSize(300, 350);
		this.setLocation(400, 200);
		this.setTitle("TCP Server");
		this.setVisible(true);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		tcpMonitor();//调用监听器方法
	}
	//监听器方法
	public void tcpMonitor() {
		try {
			ss = new ServerSocket(8888);
			bStart = true;
		} catch (IOException e) {
			e.printStackTrace();
		}
		
		try {
			while (bStart) {
				index++;
				Socket s = ss.accept();
				Client c = new Client(s);
				clients.add(c);
				
				taContent.append(s.getInetAddress().getHostAddress()
						+ " connected " + index + " clients\n");
				new Thread(c).start();
				
			}
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				ss.close();
			} catch (IOException e) {
				
				e.printStackTrace();
			}
		}
		
	}
	
	public static void main(String args[]) {
		TCPServer ts = new TCPServer();
		ts.launchFrame();
	}
	
	private class Client implements Runnable {
		DataInputStream dis = null;
		DataOutputStream dos = null;
		
		Socket s = null;
		boolean bStart = false;
		
		Client(Socket s) {
			this.s = s;
			try {
				dis = new DataInputStream(s.getInputStream());
				dos = new DataOutputStream(s.getOutputStream());
			} catch (IOException e) {
				e.printStackTrace();
			}
			
			bStart = true;
		}
		//分发信息给每个客户端
		public void sendToEveryClient(String str) {
			try {
				dos.writeUTF(str);
				dos.flush();
				
			} catch (IOException e) {
				index--;
				clients.remove(this);
				taContent.append(s.getInetAddress().getHostAddress()
						+ " exited " + index + " clients\n");
				System.out.println("对方退出了！我从List里面去掉了！");
			}
		}
		
		public void run() {
			try {
				while (bStart) {
					String str = dis.readUTF();
					System.out.println(str);
					for (int i = 0; i < clients.size(); i++) {
						Client c = clients.get(i);
						c.sendToEveryClient(str);//群发消息当然要在循环 环境里
					}
				}
			} catch (EOFException e) {
				clients.remove(this);
				taContent.append(s.getInetAddress().getHostAddress()
						+ " exited " + clients.size() + " clients\n");
				System.out.println("client closed");
			} catch (SocketException e) {
				System.out.println("client closed");
			} catch (IOException e) {
				e.printStackTrace();
			} finally {
				try {
					if (s != null)
						s.close();
					if (dis != null)
						dis.close();
					if (dos != null)
						dos.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
		
	}
	
}

客户端

package net;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;

import javax.swing.*;

public class TCPClient extends JFrame {
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	TextArea taContent = new TextArea();
	JTextField tfTxt = new JTextField(20);
	
	JButton send = new JButton("发送");
	JButton connect = new JButton("连接");
	JButton clear = new JButton("清空");
	
	boolean live = false;
	JPanel p1 = new JPanel();
	JPanel p2 = new JPanel();
	
	Socket s = null;
	DataOutputStream dos = null;
	DataInputStream dis = null;
	
	boolean bConnected = false;
	
	Thread t = new Thread(new RecToServer());
	
	public void launchFrame() {
		
		taContent.setEditable(false);
		
		p2.setLayout(new FlowLayout(FlowLayout.CENTER, 10, 5));
		p2.add(send);
		p2.add(connect);
		p2.add(clear);
		
		Container con = this.getContentPane();
		
		con.add(taContent, "North");
		con.add(tfTxt, "Center");
		con.add(p2, "South");
		
		this.setSize(300, 350);
		this.setLocation(400, 200);
		this.setTitle("Chat Client");
		
		this.setVisible(true);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		
		connect.addActionListener(new Connect());
		send.addActionListener(new SendMsg());
		clear.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				taContent.setText("");
			}
		});
	}
	
	public void connectToServer() {
		try {
			
			s = new Socket("127.0.0.1", 8888);
			dos = new DataOutputStream(s.getOutputStream());
			dis = new DataInputStream(s.getInputStream());
			
			bConnected = true;
			
		} catch (BindException e) {
			System.out.println("找不到指定的服务器");
		} catch (UnknownHostException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
	}
	
	public void disConnect() {
		try {
			if (s != null) {
				s.close();
			}
			
			if (dos != null) {
				dos.close();
			}
			if (dis != null) {
				dis.close();
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	public static void main(String args[]) {
		TCPClient tc = new TCPClient();
		tc.launchFrame();
	}
	
	private class Connect implements ActionListener {
		public void actionPerformed(ActionEvent e) {
			if (e.getActionCommand() == "连接") {
				
				connectToServer();
				try {
					t.start();
				} catch (IllegalThreadStateException ex) {
					
				}
				
				connect.setText("断开连接");
				
			} else if (e.getActionCommand() == "断开连接") {
				disConnect();
				connect.setText("连接");
			}
			
		}
	}
	
	private class SendMsg implements ActionListener {
		public void actionPerformed(ActionEvent e) {
			if (connect.getActionCommand() == "连接") {
				JOptionPane.showMessageDialog(TCPClient.this,
						"没有找到指定的服务器", "错误提示", 1);
			} else {
				String str = tfTxt.getText();
				tfTxt.setText("");
				
				try {
					dos.writeUTF(str);
					dos.flush();
				} catch (SocketException ex) {
					System.out.println("没有找到指定的服务器");
					JOptionPane.showMessageDialog(TCPClient.this,
							"没有找到指定的服务器", "错误提示", 1);
				} catch (IOException ex) {
					ex.printStackTrace();
				}
			}
			
		}
	}
	
	private class RecToServer implements Runnable {
		public void run() {
			try {
				while (bConnected) {
					String str = dis.readUTF();
					// System.out.println(str);
					
					taContent.append(str + "\n");
				}
			} catch (SocketException e) {
				System.out.println("服务器已关闭");
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
}