BBS水木清华站∶精华区

发信人: loveangel (琴儿), 信区: Java
标  题: 程序3：userlist.java,message.java,messageque.java
发信站: BBS 水木清华站 (Sun Aug 13 20:44:35 2000)

/**
* Insert the type's description here.
* Creation date: (00-8-3 17:35:04)
* @author: Administrator
*/
class Message {
private String user;
private String message;
/**
* Message constructor comment.
*/
public Message() {
super();
}
/**
* Message constructor comment.
*/
public Message(String user,String message)
{
this.user=user;
this.message=message;
}
protected String getMessage()
{
  return message;
}
protected String getUser()
{
  return user;
}
public String toString()
{
  return user+":"+message;
}
}

//messageque.java
import java.util.Hashtable;
import java.util.Enumeration;
import java.util.Vector;
/**
* Insert the type's description here.
* Creation date: (00-8-3 17:23:12)
* @author: Administrator
*/
class MessageQueue {
private Vector messageq=new Vector();
/**
* MessageQueue constructor comment.
*/
public MessageQueue() {
super();
}
protected synchronized void add(Message message)
{
  messageq.addElement(message);
  notifyAll();
}
protected synchronized Enumeration listMessages()
{
  try
  {
   if(messageq.isEmpty())
   {
    wait(30*1000);
   }
  }
  catch(InterruptedException ie)
  {
  }
  return messageq.elements();
}
protected synchronized void reset()
{
  messageq.removeAllElements();
}
}

//userlist.java
import java.util.Hashtable;
import java.util.Enumeration;
import java.util.Vector;
/**
* Insert the type's description here.
* Creation date: (00-8-3 16:31:54)
* @author: Administrator
*/
class UserList
{
private Hashtable list=new Hashtable();
private Hashtable active=new Hashtable();
/**
* UserList constructor comment.
*/
public UserList() {
super();
}
protected synchronized boolean add(String user)
{
  if(exists(user))return false;
  list.put(user,new MessageQueue());
  touch(user);
  return true;
}
protected void addMessage(Message message)
{
  Enumeration allUsers=list.keys();
  while(allUsers.hasMoreElements())
  addUserMessage((String)allUsers.nextElement(),message);
}
private void addUserMessage(String user,Message message)
{
  ((MessageQueue)list.get(user)).add(message);
}
protected synchronized boolean drop(String user)
{
  if(!exists(user))
  return false;
  list.remove(user);
  active.remove(user);
  return true;
}
protected boolean exists(String user)
{
  return list.containsKey(user);
}
protected Enumeration getMessages(String user)
{
  touch(user);
  return ((MessageQueue)list.get(user)).listMessages();
}
protected Enumeration getMessges(String user)
{
  touch(user);
  return ((MessageQueue)list.get(user)).listMessages();
}
protected synchronized Enumeration inactive(int timeout)
{
  Vector inactive=new Vector();
  long now=System.currentTimeMillis();
  long when=now-timeout;
  Enumeration users=list.keys();
  while(users.hasMoreElements())
  {
   String user=(String)users.nextElement();
   if(((Long)active.get(user)).longValue()<when)
   {
    inactive.addElement(user);
   }
  }
  return inactive.elements();
}
protected synchronized Enumeration list()
{
  return list.keys();
}
protected void resetUser(String user)
{
  ((MessageQueue)list.get(user)).reset();
}
protected synchronized void touch(String user)
{
  if(exists(user))
  {
   active.put(user,new Long(System.currentTimeMillis()));
  }
}
}

//gochat.html
<html><head>
<title>chatapplet</title>
</head>
<body>
<hr>
<applet
   name="chatapplet"
   code=chatapplet
   width=500
   height=300
   align="Middle">
</applet>
<hr>
</body>
</html>

谢谢！
请至email:wqwwlw@263.net

--

※ 来源:·BBS 水木清华站 smth.org·[FROM: 202.120.5.34]