bsservedids.java

一款即时通讯软件

package edu.ou.kmi.buddyspace.core;

/*
 * BSServedIDs.java
 *
 * Project: BuddySpace
 * (C) Copyright Knowledge Media Institute 2002
 *
 *
 * Created on 25 November 2002, 8:27
 */

import java.util.*;
import org.jabber.jabberbeans.*;
//import org.jabber.jabberbeans.util.*;
//import org.jabber.jabberbeans.Extension.*;

/**
 * <code>BSServedIDs</code> provides storing of currently served PacketIDs.
 *
 * @author  Jiri Komzak, Knowledge Media Institute, Open University, United Kingdom
 */
public class BSServedIDs {
    protected Vector ids;
    protected Vector ops;
    
    protected static final String NO_OP = "absolutely no op";
    
    /**
     * Constructor
     */
    public BSServedIDs() {
        ids = new Vector();
        ops = new Vector();
    }
    
    /**
     * Returns if given ID is served.
     */
    public synchronized boolean contains(String id) {
        Enumeration idEnum = ids.elements();
        while (idEnum.hasMoreElements()) {
            PacketID packetID = (PacketID) idEnum.nextElement();
            if ((id == null && packetID.getID() == null) ||
                (id != null && id.equals(packetID.getID())))
                
                return true;
        }
        return false;
    }
    
    /**
     * Returns operation for given served ID.
     */
    public synchronized String getOperation(String id) {
        Enumeration idEnum = ids.elements();
        int index = 0;
        while (idEnum.hasMoreElements()) {
            PacketID packetID = (PacketID) idEnum.nextElement();
            if ((id == null && packetID.getID() == null) ||
                (id != null && id.equals(packetID.getID()))) {
                
                String result = (String) ops.elementAt(index);
                return (result != NO_OP)? result : null;
            }
            index++;
        }
        return null;
    }
    
    /**
     * Adds ID.
     */
    public synchronized void add(PacketID id) {
        ids.add(id);
        ops.add(NO_OP);
    }
    
    /**
     * Adds ID.
     */
    public synchronized void add(PacketID id, String op) {
        ids.add(id);
        if (op != null) ops.add(op);
        else ops.add(NO_OP);
    }
    
    /**
     * Removes ID.
     */
    public synchronized void remove(String id) {
        Enumeration idEnum = ids.elements();
        int index = 0;
        while (idEnum.hasMoreElements()) {
            PacketID packetID = (PacketID) idEnum.nextElement();
            if ((id == null && packetID.getID() == null) ||
                (id != null && id.equals(packetID.getID()))) {
                    
                ops.removeElementAt(index);
                ids.removeElementAt(index);
                return;
            }
            index++;
        }
    }
    
}