Java聊天工具-UDP

import java.net.UnknownHostException;

public class TestMain {

	public static void main(String[] args) throws UnknownHostException{
		GuiChat gc=new GuiChat();
		gc.initSocket();
		gc.setListender();
	}
}

下面这个类主要用来实现客服端与客户端的交互，利用UDP通信，并且监听。可以在一个局域网中实现。

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.InetSocketAddress;

import javax.swing.*;

public class GuiChat extends JFrame{
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private static final int DEFAULT_PORT=8899;
	private JLabel stateLB;      //显示监听状态
	private JTextArea centerTextArea; //显示聊天记录
	private JPanel southPanel;  //最下面的面板
	private JTextArea inputTextArea; //聊天输入框
	private JPanel bottomPanel;//放置IP输入框， 按钮等
	private  JTextField ipTextField,remotePortTF;//ip 端口 输入框
	private JButton sendBT,clearBT; //发送，清除按钮
	private DatagramSocket datagramSocket;
	  GuiChat() {
		//初始化窗口
		setTitle("聊天");
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setSize(400,400);
		setResizable(false);
		stateLB=new JLabel("当前未启用");
		stateLB.setHorizontalAlignment(JLabel.RIGHT);
		centerTextArea=new JTextArea();
		centerTextArea.setEditable(false);
		centerTextArea.setBackground(new Color(211,211,211));
		southPanel=new JPanel(new BorderLayout());
		inputTextArea=new JTextArea(5,20);
		bottomPanel=new JPanel(new FlowLayout(FlowLayout.CENTER,5,5));
		ipTextField=new JTextField("127.0.0.1",8);
		remotePortTF=new JTextField(String.valueOf(DEFAULT_PORT),3);
		sendBT=new JButton("发送");
	
		clearBT=new JButton("清空");
		bottomPanel.add(ipTextField);
		bottomPanel.add(remotePortTF);
		bottomPanel.add(sendBT);
		bottomPanel.add(clearBT);
		southPanel.add(new JScrollPane(inputTextArea),BorderLayout.CENTER);
		southPanel.add(bottomPanel,BorderLayout.SOUTH);
		add(stateLB,BorderLayout.NORTH);
		add(new JScrollPane(centerTextArea),BorderLayout.CENTER);
		add(southPanel,BorderLayout.SOUTH);
		setVisible(true);
		
	}
	  public void setListender() {
		  sendBT.addActionListener(new ActionListener() {
			
			@Override
			public void actionPerformed(ActionEvent e) {
				final String ipAdress=ipTextField.getText();
				final String remotePort=remotePortTF.getText();
				if(ipAdress==null||remotePort==null) {
					JOptionPane.showMessageDialog(GuiChat.this,"请输入正确的IP和端口号");
					return;
				}
				if(datagramSocket==null||datagramSocket.isClosed()) {
					JOptionPane.showMessageDialog(GuiChat.this,"监听失败!");
					return;
				}
				byte[] buf=inputTextArea.getText().getBytes();
				try {
					centerTextArea.append("我对"+ipAdress+":"+remotePort+"说：\n"+
				inputTextArea.getText()+"\n\n");
					centerTextArea.setCaretPosition(centerTextArea.getText().length());
					datagramSocket.send(new DatagramPacket(buf, buf.length,InetAddress.getByName(ipAdress)
							,Integer.parseInt(remotePort)));
					inputTextArea.setText("");
				} catch (Exception e2) {
					JOptionPane.showMessageDialog(GuiChat.this,"未发送成功!");
					e2.printStackTrace();
				}
			}
		});
		  clearBT.addActionListener(new ActionListener() {       //为清空按钮添加事件
			
			@Override
			public void actionPerformed(ActionEvent e) {
				centerTextArea.setText("");	
			}
		});
	  }
	  public void initSocket() {  //设置端口号
		  int port=DEFAULT_PORT;
		  while(true) {
			  try {
				if(datagramSocket!=null&&!datagramSocket.isClosed()) {
					datagramSocket.close();
				}
				try {
					port=Integer.parseInt(JOptionPane.showInputDialog(this,"请输入端口号","端口号",JOptionPane.QUESTION_MESSAGE));
					if(port<1||port>65535) {
						throw  new RuntimeException("端口号超范围！");
					}		
				}catch(Exception e3) {
					JOptionPane.showMessageDialog(null, "请重新输入！");
					continue;
				}
				datagramSocket=new DatagramSocket(port);
				startListener();
				stateLB.setText("已经在"+port+"监听");
				break;
			} catch (Exception e) {
				JOptionPane.showMessageDialog(this, "监听失败，请重新设置端口");
				stateLB.setText("当前未启动监听！");
			}
		  }
	  }
	public void startListener() {  //监听端口 用来接收消息
	  new Thread() {
		  private DatagramPacket p;
		  public void run() {
			  byte[] buf=new byte[1024];
			  p=new DatagramPacket(buf, buf.length);
			  while(!datagramSocket.isClosed()) {
				try {
					datagramSocket.receive(p);
					centerTextArea.append(p.getAddress().getHostAddress()+":"+((InetSocketAddress) p.getSocketAddress()).getPort()
							+"对我说：\n"+new String (p.getData(),0,p.getLength())+"\n\n");
					centerTextArea.setCaretPosition(centerTextArea.getText().length());
					
				} catch (Exception e) {
					e.printStackTrace();
				}  
			  }
		  }
	  }.start();
		
	}
}