lanchat.java

疯狂Java讲义_源码(含Java设计模式CHM

import java.util.*;
import java.awt.*;
import java.net.*;
import java.text.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;

/**
 * Description:
 * <br/>Copyright (C), 2005-2008, Yeeku.H.Lee
 * <br/>This program is protected by copyright laws.
 * <br/>Program Name:
 * <br/>Date:
 * @author  Yeeku.H.Lee [e-mail]
 * @version  1.0
 */

public class LanChat extends JFrame
{
	private DefaultListModel listModel = new DefaultListModel();
	//定义一个JList对象
	private JList friendsList = new JList(listModel);
	//定义一个用于格式化日期的格式器
	private DateFormat formatter = DateFormat.getDateTimeInstance(); 

	public LanChat()
	{
		super("局域网聊天");
		//设置该JList使用ImageCellRenderer作为单元格绘制器
		friendsList.setCellRenderer(new ImageCellRenderer()); 
		listModel.addElement(new UserInfo("all" , "所有人" , null , -2000));
		friendsList.addMouseListener(new ChangeMusicListener());
		add(new JScrollPane(friendsList));
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setBounds(2, 2, 160 , 600);
	}
	//向用户列表中添加用户
	public void addUser(UserInfo user)
	{
		listModel.addElement(user);
	}
	//从用户列表中删除用户
	public void removeUser(int pos)
	{
		listModel.removeElementAt(pos);
	}
	//根据地址来查询用户
	public UserInfo getUserBySocketAddress(SocketAddress address)
	{
		for (int i = 1 ; i < getUserNum() ; i++)
		{
			UserInfo user = getUser(i);
			if (user.getAddress() != null && 
				user.getAddress().equals(address))
			{
				return user;
			}
		}
		return null;
	}
	//—————————下面两个方法是对ListModel的包装—————————
	//获取该聊天窗口的用户数量
	public int getUserNum()
	{
		return listModel.size();
	}
	//获取指定位置的用户
	public UserInfo getUser(int pos)
	{
		return (UserInfo)listModel.elementAt(pos);
	}
	//实现JList上的鼠标双击监听器
	class ChangeMusicListener extends MouseAdapter
	{
		public void mouseClicked(MouseEvent e)
		{
			//如果鼠标的击键次数大于2
			if (e.getClickCount() >= 2)
			{
				//取出鼠标双击时选中的列表项
				UserInfo user = (UserInfo)friendsList.getSelectedValue();
				//如果该列表项对应用户的交谈窗口为null
				if (user.getChatFrame() == null)
				{
					//为该用户创建一个交谈窗口，并让该用户引用该窗口
					user.setChatFrame(new ChatFrame(null , user));
				}
				//如果该用户的窗口没有显示，则让该用户的窗口显示出来
				if (!user.getChatFrame().isShowing())
				{
					user.getChatFrame().setVisible(true);
				}
			}
		}
	}
	/**
	 * 处理网络数据报，该方法将根据聊天信息得到聊天者，
	 * 并将信息显示在聊天对话框中。
	 * @param packet 需要处理的数据报
	 * @param single 该信息是否为私聊信息
	 */
	public void processMsg(DatagramPacket packet , boolean single)
	{
		//获取该发送该数据报的SocketAddress
		InetSocketAddress srcAddress = (InetSocketAddress)packet.getSocketAddress();
		//如果是私聊信息，则该Packet获取的是DatagramSocket的地址，将端口减1才是
		//对应的MulticastSocket的地址
		if (single)
		{
			srcAddress = new InetSocketAddress(srcAddress.getHostName(),
				srcAddress.getPort() - 1);
		}
		UserInfo srcUser = getUserBySocketAddress(srcAddress);
		if (srcUser != null)
		{
			//确定消息将要显示到哪个用户对应窗口上。
			UserInfo alertUser = single ? srcUser : getUser(0);
			//如果该用户对应的窗口为空，显示该窗口
			if (alertUser.getChatFrame() == null)
			{
				alertUser.setChatFrame(new ChatFrame(null , alertUser));
			}
			//定义添加的提示信息
			String tipMsg = single ? "对您说：" : "对大家说：";
			//显示提示信息
			alertUser.getChatFrame().addString(srcUser.getName() + tipMsg
				+ "......................(" + formatter.format(new Date()) + ")\n"
				+ new String(packet.getData() , 0 , packet.getLength()) + "\n");
			if (!alertUser.getChatFrame().isShowing())
			{
				alertUser.getChatFrame().setVisible(true);
			}
		}
	}
	//主方法，程序的入口
	public static void main(String[] args) 
	{
		LanChat lc = new LanChat();
		new LoginFrame(lc , "请输入用户名、头像后登陆");
	}
}
//定义用于改变JList列表项外观的类
class ImageCellRenderer extends JPanel implements ListCellRenderer
{
	private ImageIcon icon;
	private String name;
	//定义绘制单元格时的背景色
	private Color background;
	//定义绘制单元格时的前景色
	private Color foreground;

	public Component getListCellRendererComponent(JList list, Object value, int index, 
	  boolean isSelected, boolean cellHasFocus)
	{
		UserInfo userInfo = (UserInfo)value;
		icon = new ImageIcon("ico/" + userInfo.getIcon() + ".gif");
		name = userInfo.getName();
		background = isSelected ? list.getSelectionBackground() : list.getBackground();
		foreground = isSelected ? list.getSelectionForeground() : list.getForeground();
		//返回该JPanel对象作为单元格绘制器
		return this;
	}
	//重写paintComponent方法，改变JPanel的外观
	public void paintComponent(Graphics g)
	{
		int imageWidth = icon.getImage().getWidth(null);
		int imageHeight = icon.getImage().getHeight(null);
		g.setColor(background);
		g.fillRect(0, 0, getWidth(), getHeight());
		g.setColor(foreground);
		//绘制好友图标
		g.drawImage(icon.getImage() , getWidth() / 2 - imageWidth / 2 , 10 , null);
		g.setFont(new Font("SansSerif" , Font.BOLD , 18));
		//绘制好友用户名
		g.drawString(name, getWidth() / 2 - name.length() * 10 , imageHeight + 30 );
	}
	//通过该方法来设置该ImageCellRenderer的最佳大小
	public Dimension getPreferredSize()
	{  
		return new Dimension(60, 80);
	}
}