onlineuserlistener.java

struts+javabean写的聊天程序

package com.chat.util;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;

import org.apache.struts.util.LabelValueBean;

import com.chat.vo.User;

public class OnlineUserListener implements HttpSessionListener {

	private static int onlineUsers = 0;

	private static Map<String, String> users = new HashMap<String, String>();

	private static List<LabelValueBean> list = new ArrayList<LabelValueBean>();

	public static String getUsernameByUserid(String userid) {
		return users.get(userid);
	}
	
	public static List getUsers() {
		list.clear();
		String[][] string = SuperUtil.mapToPlanarArray(users);
		for(int i=0; i<users.size(); i++) {
			list.add(new LabelValueBean(string[i][0],string[i][1]));
		}
		return list;
	}
	
	public void sessionCreated(HttpSessionEvent arg0) {
		System.out.println("Session创建" + arg0.getSession().getId());
	}

	@SuppressWarnings("unchecked")
	public static void addUser(User user) {
		if (!(users.containsKey(user.getUserid()))){
			users.put(user.getUserid(), user.getUsername());
			onlineUsers++;
			System.out.println(user);
		} else{
			System.out.println("ID为: " + user.getUserid() + "用户已经存在");
		}
	}

	public void sessionDestroyed(HttpSessionEvent arg0) {
		System.out.println("Session销毁" + arg0.getSession().getId());
	}

	public static void removeUser(String userid) {
		if (users.containsKey(userid)){
			users.remove(userid);
			onlineUsers--;
		} else{
			System.out.println("用户" + userid + "已经不存在");
		}
	}

	public static int getOnlineUsers() {
		return onlineUsers;
	}

//	public static Map getUsers() {
//		return users;
//	}

}