import java.net.DatagramPacket;
import java.net.InetAddress;
import java.net.MulticastSocket;
import java.text.DateFormat;

import javax.swing.UIManager;

/**
 * UDP多播聊天程序.
 * @author BeanSoft
 */
public class UDPChatFrame extends javax.swing.JFrame {
	// 接收數據的線程
	class ReaderThread extends Thread {

		public void run() {
			while (socket != null) {
				try {
					byte[] buf = new byte[1024];
					DatagramPacket recv = new DatagramPacket(buf, buf.length);
					socket.receive(recv);
					addChatText(new String(recv.getData()));
				} catch (Exception ex) {
				}
			}
		}

	}

	private InetAddress group = null;// 多播地址
	private MulticastSocket socket = null;// 多播套接字
	private String username;// 用戶名
	private int port;// 端口

	/** Creates new form UDPChatFrame */
	public UDPChatFrame() {
		initComponents();
		setIconImage(new javax.swing.ImageIcon(getClass().getResource(
				"/icons/icon.png")).getImage());
		// 啟動時默認顯示 Office 2003 外觀
		changeLookAndFeel("org.fife.plaf.Office2003.Office2003LookAndFeel");
		jRadioButtonMenuItemOffice2003.setSelected(true);
	}

	/**
	 * 根據外觀類名更換界面風格。
	 * 
	 * @param lafClassName
	 *            外觀類名
	 */
	void changeLookAndFeel(String lafClassName) {
		try {
			javax.swing.UIManager.setLookAndFeel(lafClassName);
			javax.swing.SwingUtilities.updateComponentTreeUI(this);
		} catch (Exception e) {
			e.printStackTrace();
			try {
				javax.swing.UIManager.setLookAndFeel(javax.swing.UIManager
						.getCrossPlatformLookAndFeelClassName());
				javax.swing.SwingUtilities.updateComponentTreeUI(this);
			} catch (Exception e1) {
				e1.printStackTrace();
			}
		}
	}

	/**
	 * 向聊天區域添加信息，加上時間戳。
	 * 
	 * @param text
	 *            要添加的文字信息
	 */
	private void addChatText(String text) {
		if (text != null) {
			text = text.replaceAll("\0", "");
		}
		DateFormat df = DateFormat.getDateTimeInstance();
		String msg = df.format(new java.util.Date()) + " " + text + "\n";
		jTextAreaHistory.append(msg);
		System.out.println(msg);
	}

	// 加入聊天室
	void join() {
		username = this.jTextFieldUsername.getText();
		if (username.equals("")) {
			addChatText("請你務必首先輸入一個名字.");
			return;
		}
		try {
			addChatText("嘗試進入聊天室...");
			group = InetAddress.getByName(jTextFieldIP.getText());
			port = Integer.parseInt(jTextFieldPort.getText());
			socket = new MulticastSocket(port);
			socket.joinGroup(group);
			String message = username + "[" + InetAddress.getLocalHost()
					+ "] 進入聊天室 " + group + "! 端口號" + jTextFieldPort.getText()
					+ ".";
			DatagramPacket hi = new DatagramPacket(message.getBytes(), message
					.getBytes().length, group, port);
			socket.send(hi);
			jTextFieldUsername.setEditable(false);
			jButtonSend.setEnabled(true);
			new ReaderThread().start();
		} catch (Exception ex) {
			addChatText("無法進入聊天室:" + ex);
			ex.printStackTrace();
		}
	}

	// 發送聊天信息
	void send() {
		if (socket == null)
			return;
		try {
			String message = username + "[" + InetAddress.getLocalHost()
					+ "] : " + jTextFieldMessage.getText();
			DatagramPacket hi = new DatagramPacket(message.getBytes(), message
					.getBytes().length, group, port);
			socket.send(hi);
			jTextFieldMessage.requestFocus();
			jTextFieldMessage.selectAll();
		} catch (Exception ex) {
			addChatText("無法發送消息:" + ex);
		}
	}

	// 離開聊天室
	void leave() {
		if (socket == null)
			return;
		try {
			addChatText("嘗試離開聊天室...");
			String message = username + " 已經離開了聊天室 " + group + "!\n";
			DatagramPacket hi = new DatagramPacket(message.getBytes(), message
					.getBytes().length, group, port);
			socket.send(hi);
			socket.leaveGroup(group);
			socket.close();
			socket = null;
			jTextFieldUsername.setEditable(true);
			jButtonSend.setEnabled(false);
			addChatText("你已經離開了聊天室!");
		} catch (Exception ex) {
			addChatText("無法離開聊天室:" + ex);
			ex.printStackTrace();
		}
	}

	//GEN-BEGIN:initComponents
	// <editor-fold defaultstate="collapsed" desc="Generated Code">
	private void initComponents() {

		buttonGroupLAF = new javax.swing.ButtonGroup();
		jLabelIP = new javax.swing.JLabel();
		jTextFieldIP = new javax.swing.JTextField();
		jLabelPort = new javax.swing.JLabel();
		jTextFieldPort = new javax.swing.JTextField();
		jLabelUsername = new javax.swing.JLabel();
		jTextFieldUsername = new javax.swing.JTextField();
		jTextFieldMessage = new javax.swing.JTextField();
		jButtonSend = new javax.swing.JButton();
		jScrollPane1 = new javax.swing.JScrollPane();
		jTextAreaHistory = new javax.swing.JTextArea();
		jMenuBar = new javax.swing.JMenuBar();
		jMenuFile = new javax.swing.JMenu();
		jMenuItemConnect = new javax.swing.JMenuItem();
		jMenuItemLeave = new javax.swing.JMenuItem();
		jSeparatorFile = new javax.swing.JSeparator();
		jMenuItemQuit = new javax.swing.JMenuItem();
		jMenuOperation = new javax.swing.JMenu();
		jMenuItemClear = new javax.swing.JMenuItem();
		jMenuChangeLAF = new javax.swing.JMenu();
		jRadioButtonMenuItemOffice2003 = new javax.swing.JRadioButtonMenuItem();
		jRadioButtonMenuItemSystem = new javax.swing.JRadioButtonMenuItem();
		jRadioButtonMenuItemDefault = new javax.swing.JRadioButtonMenuItem();
		jMenuHelp = new javax.swing.JMenu();
		jMenuItemHelpContents = new javax.swing.JMenuItem();
		jMenuItemAbout = new javax.swing.JMenuItem();

		setDefaultCloseOperation(javax.swing.WindowConstants.DO_NOTHING_ON_CLOSE);
		setTitle("\u591a\u70b9\u4f20\u9001\u6570\u636e\u62a5\u804a\u5929\u7a0b\u5e8f - IP\u5730\u5740\u8303\u56f4: 224.0.0.1 ~ 239.255.255.255");
		addWindowListener(new java.awt.event.WindowAdapter() {
			public void windowClosing(java.awt.event.WindowEvent evt) {
				formWindowClosing(evt);
			}
		});

		jLabelIP.setText("IP:");

		jTextFieldIP.setText("225.0.0.1");

		jLabelPort.setText("\u7aef\u53e3:");

		jTextFieldPort.setText("4000");

		jLabelUsername.setText("\u7528\u6237\u540d:");

		jTextFieldUsername.setText("\u65e0\u540d");

		jTextFieldMessage
				.addActionListener(new java.awt.event.ActionListener() {
					public void actionPerformed(java.awt.event.ActionEvent evt) {
						jTextFieldMessageActionPerformed(evt);
					}
				});

		jButtonSend.setIcon(new javax.swing.ImageIcon(getClass().getResource(
				"/icons/send.gif"))); // NOI18N
		jButtonSend.setMnemonic('S');
		jButtonSend.setText("\u53d1\u9001(S)");
		jButtonSend.addActionListener(new java.awt.event.ActionListener() {
			public void actionPerformed(java.awt.event.ActionEvent evt) {
				jButtonSendActionPerformed(evt);
			}
		});

		jTextAreaHistory.setColumns(20);
		jTextAreaHistory.setRows(5);
		jScrollPane1.setViewportView(jTextAreaHistory);

		jMenuFile.setText("\u6587\u4ef6(F)");

		jMenuItemConnect.setAccelerator(javax.swing.KeyStroke.getKeyStroke(
				java.awt.event.KeyEvent.VK_E,
				java.awt.event.InputEvent.CTRL_MASK));
		jMenuItemConnect.setIcon(new javax.swing.ImageIcon(getClass()
				.getResource("/icons/connect.gif"))); // NOI18N
		jMenuItemConnect.setText("\u8fde\u63a5");
		jMenuItemConnect.addActionListener(new java.awt.event.ActionListener() {
			public void actionPerformed(java.awt.event.ActionEvent evt) {
				jMenuItemConnectActionPerformed(evt);
			}
		});
		jMenuFile.add(jMenuItemConnect);

		jMenuItemLeave.setAccelerator(javax.swing.KeyStroke.getKeyStroke(
				java.awt.event.KeyEvent.VK_D,
				java.awt.event.InputEvent.CTRL_MASK));
		jMenuItemLeave.setIcon(new javax.swing.ImageIcon(getClass()
				.getResource("/icons/disConnect.gif"))); // NOI18N
		jMenuItemLeave.setText("\u79bb\u5f00");
		jMenuItemLeave.addActionListener(new java.awt.event.ActionListener() {
			public void actionPerformed(java.awt.event.ActionEvent evt) {
				jMenuItemLeaveActionPerformed(evt);
			}
		});
		jMenuFile.add(jMenuItemLeave);
		jMenuFile.add(jSeparatorFile);

		jMenuItemQuit.setAccelerator(javax.swing.KeyStroke.getKeyStroke(
				java.awt.event.KeyEvent.VK_Q,
				java.awt.event.InputEvent.CTRL_MASK));
		jMenuItemQuit.setIcon(new javax.swing.ImageIcon(getClass().getResource(
				"/icons/exit.png"))); // NOI18N
		jMenuItemQuit.setText("\u9000\u51fa");
		jMenuItemQuit.addActionListener(new java.awt.event.ActionListener() {
			public void actionPerformed(java.awt.event.ActionEvent evt) {
				jMenuItemQuitActionPerformed(evt);
			}
		});
		jMenuFile.add(jMenuItemQuit);

		jMenuBar.add(jMenuFile);

		jMenuOperation.setText("\u64cd\u4f5c(O)");

		jMenuItemClear.setIcon(new javax.swing.ImageIcon(getClass()
				.getResource("/icons/clear.gif"))); // NOI18N
		jMenuItemClear.setText("\u6e05\u7a7a\u8bb0\u5f55");
		jMenuItemClear.addActionListener(new java.awt.event.ActionListener() {
			public void actionPerformed(java.awt.event.ActionEvent evt) {
				jMenuItemClearActionPerformed(evt);
			}
		});
		jMenuOperation.add(jMenuItemClear);

		jMenuChangeLAF.setText("\u66f4\u6539\u754c\u9762");

		buttonGroupLAF.add(jRadioButtonMenuItemOffice2003);
		jRadioButtonMenuItemOffice2003.setSelected(true);
		jRadioButtonMenuItemOffice2003.setText("Office2003");
		jRadioButtonMenuItemOffice2003
				.addActionListener(new java.awt.event.ActionListener() {
					public void actionPerformed(java.awt.event.ActionEvent evt) {
						jRadioButtonMenuItemOffice2003ActionPerformed(evt);
					}
				});