下午在公司闲的蛋疼，花了2个小时整了个局域网的聊天工具玩。界面模仿飞鸽传书，基于UDP协议，只有最基本的聊天功能。代码结构也比较乱，有兴趣的可以拿去玩玩。
- Java code
import java.io.IOException;import java.net.DatagramPacket;import java.net.DatagramSocket;import java.net.InetAddress;import java.net.SocketException;import java.text.SimpleDateFormat;import java.util.Date;import java.util.Hashtable;import java.util.Map;import java.util.UUID;import javax.swing.JFrame;import javax.swing.JOptionPane;import javax.swing.JScrollPane;import javax.swing.JTable;import javax.swing.JTextArea;import javax.swing.JButton;import javax.swing.border.EtchedBorder;import javax.swing.table.DefaultTableModel;import java.awt.SystemColor;import javax.swing.ScrollPaneConstants;import java.awt.Color;import java.awt.event.KeyAdapter;import java.awt.event.KeyEvent;import java.awt.event.MouseAdapter;import java.awt.event.MouseEvent;import java.awt.event.WindowAdapter;import java.awt.event.WindowEvent;import javax.swing.JLabel;public class Msg extends JFrame { private static final long serialVersionUID = 3170335398335303363L; private String uname = "qq"; private DatagramSocket server;// UDP private InetAddress broadcastAddress;// 廣播地址 private int port;// 監聽端口 private final Map<String, UserInfo> userTable = new Hashtable<String, UserInfo>();// 用戶列表 private final String guid = UUID.randomUUID().toString().replace("-", "").toUpperCase();// 本機唯一標識 private JTable table; private JTextArea textArea; private JLabel lblNewLabel_1; public Msg() throws SocketException { this(5413); } public Msg(int port) throws SocketException { this.port = port; getContentPane().setLayout(null); getContentPane().setBackground(SystemColor.control); JButton btnNewButton = new JButton("刷新"); btnNewButton.addMouseListener(new MouseAdapter() { public void mouseClicked(MouseEvent e) { refresh(); } }); btnNewButton.setBackground(SystemColor.control); btnNewButton.setBounds(299, 119, 83, 28); getContentPane().add(btnNewButton); JScrollPane scrollPane = new JScrollPane(); scrollPane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS); scrollPane.setBounds(12, 12, 275, 135); getContentPane().add(scrollPane); table = new JTable(new DefaultTableModel(new Object[][] { { null, null, null }, { null, null, null }, { null, null, null }, { null, null, null }, { null, null, null }, { null, null, null }, { null, null, null }, { null, null, null }, { null, null, null }, }, new String[] { "\u7528\u6236\u540D", "IP", "GUID" }) { private static final long serialVersionUID = -6259343924352571655L; public boolean isCellEditable(int row, int column) { return false; } }); table.setBackground(new Color(255, 255, 255)); scrollPane.setViewportView(table); table.setBorder(new EtchedBorder(EtchedBorder.LOWERED, null, null)); JScrollPane scrollPane_1 = new JScrollPane(); scrollPane_1.setBounds(12, 159, 370, 104); getContentPane().add(scrollPane_1); textArea = new JTextArea(); textArea.setLineWrap(true); textArea.addKeyListener(new KeyAdapter() { public void keyPressed(KeyEvent e) { if ((e.isControlDown() && e.getKeyCode() == KeyEvent.VK_ENTER) || (e.isAltDown() && e.getKeyCode() == KeyEvent.VK_S)) { sendMessage(); } } }); scrollPane_1.setViewportView(textArea); JButton button = new JButton("發送"); button.setBackground(SystemColor.control); button.setBounds(141, 275, 83, 28); button.addMouseListener(new MouseAdapter() { public void mouseClicked(MouseEvent e) { sendMessage(); } }); getContentPane().add(button); JButton button_1 = new JButton("關閉"); button_1.setBackground(SystemColor.control); button_1.setBounds(22, 275, 83, 28); button_1.addMouseListener(new MouseAdapter() { public void mouseClicked(MouseEvent e) { Msg.this.dispatchEvent(new WindowEvent(Msg.this, WindowEvent.WINDOW_CLOSING)); } }); getContentPane().add(button_1); JLabel lblNewLabel = new JLabel("當前在線人數"); lblNewLabel.setBounds(299, 29, 83, 18); getContentPane().add(lblNewLabel); lblNewLabel_1 = new JLabel("0"); lblNewLabel_1.setBounds(305, 59, 55, 18); getContentPane().add(lblNewLabel_1); JLabel lblNewLabel_2 = new JLabel("Alt+S或Ctrl+Enter發送"); lblNewLabel_2.setBounds(242, 280, 140, 18); getContentPane().add(lblNewLabel_2); this.setSize(400, 348); setBackground(SystemColor.control); setResizable(false); setTitle("局域網聊天"); this.setLocationRelativeTo(null); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); this.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { try { sendBroadcast((guid + "2").getBytes(), broadcastAddress); } catch (Exception e2) { } } }); try { uname = JOptionPane.showInputDialog("請輸入你的暱稱"); uname = uname == null ? "匿名" : uname; server = new DatagramSocket(port); broadcastAddress = InetAddress.getByName("255.255.255.255"); new AcceptBroadcastThread().start();// 啟動監聽 sendBroadcast((guid + "0" + uname).getBytes(), broadcastAddress);// 發送全網廣播，通知上線 } catch (Exception e) { JOptionPane.showMessageDialog(this, "端口" + port + "被佔用！"); System.exit(0); } } /** * 向外發送數據 * * @param data * @param address * @throws IOException */ public void sendBroadcast(byte[] data, InetAddress address) throws IOException { DatagramPacket dp = new DatagramPacket(data, data.length, address, port); server.send(dp); } /** * 刷新列表 */ public void refresh() { // 清空列表 userTable.clear(); DefaultTableModel tableModel = ((DefaultTableModel) table.getModel()); for (int j = table.getRowCount(); j > 0; j--) { tableModel.removeRow(j - 1); } try { sendBroadcast((guid + "3" + uname).getBytes(), broadcastAddress);// 重新發送全網廣播，通知上線 } catch (Exception e) { } } public void alertMessage(final String msg) { new Thread() { public void run() { JOptionPane.showMessageDialog(Msg.this, msg); }; }.start(); } /** * 發送文字消息 */ public void sendMessage() { int[] selectRows = table.getSelectedRows(); DefaultTableModel tableModel = (DefaultTableModel) table.getModel(); String msg = guid + "1" + textArea.getText(); byte[] data = string2Bytes(msg); for (int i = 0, j = selectRows.length; i < j; i++) { String key = (String) tableModel.getValueAt(selectRows[i], 2); UserInfo ui = key == null ? null : userTable.get(key); if (ui != null) { try { textArea.setText(""); sendBroadcast(data, ui.getIpAddress()); } catch (Exception e) { JOptionPane.showMessageDialog(this, "發送消息到" + ui.getName() + "(" + ui.getIpAddress().getHostAddress() + ")失敗！", "發送失敗", JOptionPane.ERROR_MESSAGE); } } } } private byte[] string2Bytes(String str) { try { return str.getBytes("UTF-8"); } catch (Exception e) { } return null; } class UserInfo { private String guid; private String name; private InetAddress ipAddress; public String getGuid() { return guid; } public void setGuid(String guid) { this.guid = guid; } public String getName() { return name; } public void setName(String name) { this.name = name; } public InetAddress getIpAddress() { return ipAddress; } public void setIpAddress(InetAddress ipAddress) { this.ipAddress = ipAddress; } } class AcceptBroadcastThread extends Thread { public void run() { while (true) { try { DatagramPacket dp = new DatagramPacket(new byte[1024], 1024); server.receive(dp); String msg = new String(dp.getData(), 0, dp.getLength(), "UTF-8");// 解析廣播數據包 String uid = msg.substring(0, 32); String type = msg.substring(32, 33); if (type.equals("0") || type.equals("3")) { UserInfo ui = new UserInfo(); ui.setGuid(uid); ui.setName(msg.substring(33)); ui.setIpAddress(dp.getAddress()); // 刷新請求，只響應不做其他處理 if (userTable.containsKey(ui.getGuid()) && type.equals("3")) { sendBroadcast((guid + "0" + uname).getBytes(), broadcastAddress); } // 上線通知 if (!userTable.containsKey(ui.getGuid())) { userTable.put(ui.getGuid(), ui);// 將新用戶添加到用戶表 lblNewLabel_1.setText("" + userTable.size()); sendBroadcast((guid + "0" + uname).getBytes(), broadcastAddress);// 響應非本機廣播 ((DefaultTableModel) table.getModel()).insertRow(0, new String[] { ui.getName(), ui.getIpAddress().getHostAddress(), ui.getGuid() }); } } else if (type.equals("1")) { UserInfo ui = userTable.get(uid); alertMessage(ui.getName() + "(" + ui.getIpAddress().getHostAddress() + ")-" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "\r\n" + msg.substring(33)); } else { userTable.remove(uid);// 移除用戶 lblNewLabel_1.setText("" + userTable.size()); DefaultTableModel tableModel = ((DefaultTableModel) table.getModel()); for (int i = 0, j = table.getRowCount(); i < j; i++) { if (tableModel.getValueAt(i, 2).equals(uid)) { tableModel.removeRow(i); } } } } catch (Exception e) { } } } } public static void main(String[] args) throws Exception { Msg msg = new Msg(); msg.setVisible(true); }}