随机聊天

最近流行omegle，我也做了一个:

地址：http://hdc1112.appspot.com/client/client.html

核心代码：

package hust.ning;

import hust.ning.jdo.DAO;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.UUID;
import java.util.logging.Logger;


public class ChatApp {
	private static final Logger log = Logger.getLogger(ChatApp.class.getName());
	private static ChatApp instance = null;
	
	private ChatApp (){
//		new Timer().schedule(new TimerTask(){
//			@Override
//			public void run() {
//				checkTimeOut();				
//			}
//		}, 60*1000,60*1000);//60s，不准我用Timer，我在adduser达到1000的时候check。
	}
	
	private void checkTimeOut()
	{
		log.info("checkTimeOut");
		for(String k :activity.keySet())
		{
			if (!activity.get(k))
				logout(k);
			else 
				activity.put(k, false);
		}
	}
	public static ChatApp getInstance()
	{
		if (instance==null)
			instance=new ChatApp();
		return instance;
	}
	private static int i = DAO.getUserCount();
	private String genUUID()
	{
		return UUID.randomUUID().toString()+"_U"+i++;
	}
	public int getUserCount()
	{
		return i;
	}
	public int getCurrentUserCount()
	{
		if (singleUser==null)
			return p2pmap.size();
		else 
			return p2pmap.size()+1;
	}
	
	private Map<String,String> p2pmap = new HashMap<String, String>();
	
	/**
	 * UserID -> content的map.
	 */
	private Map<String,List<String>> contents =new HashMap<String, List<String>>();
	private Map<String ,Integer> counter = new HashMap<String, Integer>();//用于超时管理
	private Map<String ,Boolean> activity = new HashMap<String, Boolean>();//用于超时管理。
	private String singleUser;
	
	public String getSingleUser ()
	{
		return singleUser;
	}
	public synchronized String login()
	{
		String id = this.genUUID();
		counter.put(id, 0);
		activity.put(id, true);
		log.info("USER LOGIN:"+id);
		DAO.saveChat(id, "SYSTEM:LOGIN");
		if (null == singleUser)
		{
			singleUser=id;
			return id;
		}
		log.info("PUT user to map :"+id +"<->"+ singleUser);
		p2pmap.put(id, singleUser);
		p2pmap.put(singleUser, id);
		singleUser=null;
		if (i%1024==0)
			checkTimeOut();
		return id;
	}
	

 	public /*synchronized */void addChat(String uid,String content)
	{
		if (!p2pmap.containsKey(uid))
			return ;//one of the peer is offline.

 		counter.put(uid, 0);//清零。
		log.info(""+uid+":"+content);
		DAO.saveChat(uid, content);
		if (!contents.containsKey(uid))
			contents.put(uid, new ArrayList<String>());
		contents.get(uid).add(content);
	}
	public /*synchronized */List <String> getChat(String uid){
		if (!activity.containsKey(uid))
			return null;//null表示已经logout.
		activity.put(uid, true);
		int x = counter.get(uid);
		if (x>20)//如果收到100个getNotification而没有一个addChat()，认为用户断线。
		{
			logout(uid);
			return null;
		}
		counter.put(uid, x+1);
		
		if (!p2pmap.containsKey(uid))
			return null;//one of the peer is offline.
		
		String peer= p2pmap.get(uid);
		List <String >rst = contents.get(peer);
		if (rst==null)
			rst= new ArrayList<String>();
//		log.info(":::"+rst);
		
		contents.remove(peer);
		return rst;
	}
	public void logout(String uid)
	{
		if (null!=p2pmap.get(uid))
			logout2(p2pmap.get(uid));
		logout2(uid);
	}
	private void logout2(String uid)
	{
		log.info("USER LOGOUT:"+uid );
		if (uid==null)
			return ;
		DAO.saveChat(uid, "SYSTEM:LOGOUT");
		if (uid.equals(singleUser))
			singleUser=null;
		
		p2pmap.remove(uid);
		counter.remove(uid);
		contents.remove(uid);
		activity.remove(uid);
	}
}

 

欢迎讨论。

 

GAE 没法支持comet，

不过现在了解到comet这样的技术，以后做类似项目的时候可以用了。