chatservice.java

用ajax技术实现的简单的j2ee聊天室

package servlet;

import java.util.LinkedList;

public class ChatService {
	
	private static ChatService cs;
	private LinkedList<String> chatMsg;
	public static ChatService instance() {
		if(cs == null){
			cs = new ChatService();
		}
		return cs;
	}

	public void addMsg(String user, String msg) {
		if(chatMsg == null){
			chatMsg = new LinkedList<String>();
		}
		if(chatMsg.size() > 40){
			chatMsg.removeFirst();
		}
		chatMsg.add(user + "说: " + msg);
	}

	public String getMsg() {
		if(chatMsg == null){
			chatMsg = new LinkedList<String>();
			return "";
		}
		String result = "";
		for(String tmp : chatMsg){
			result += tmp + "\n";
		}
		return result;
	}

}