jahiacachefactory.java

java 写的一个新闻发布系统

//
//                                   ____.
//                       __/\ ______|    |__/\.     _______
//            __   .____|    |       \   |    +----+       \
//    _______|  /--|    |    |    -   \  _    |    :    -   \_________
//   \\______: :---|    :    :           |    :    |         \________>
//           |__\---\_____________:______:    :____|____:_____\
//                                      /_____|
//
//                 . . . i n   j a h i a   w e   t r u s t . . .
//

//
//  JahiaCache Factory
//  DJ      06.01.2001+
//
//  createJahiaCache (ID, JahiaCacheIO)
//

package org.jahia.services.cache;

import java.util.*;                     // Vector

import org.jahia.utils.*;           // JahiaConsole
import org.jahia.data.fields.*;     // JahiaField
import org.jahia.data.cache.*;      // JahiaCache, JahiaCacheIO
import org.jahia.services.*;        // ServicesRegistry
import org.jahia.exceptions.*;      // JahiaException

/**
 * <p>Title: </p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2002</p>
 * <p>Company: Jahia Inc.</p>
 * @author David Jilli
 * @todo FIXME we should really only store an common interface in here !!
 */
public class JahiaCacheFactory {

    private static  	JahiaCacheFactory   m_instance   = null;

    // containing every JahiaCache's created


    /**
     * @associates JahiaCache
     */
    private Hashtable	allCaches = new Hashtable();

   /***
    * constructor
    */
    private JahiaCacheFactory()
    {
        JahiaConsole.println( "CacheFactory", "***** Starting Cache Factory *****" );
    } // end constructor

    /***
     * getInstance
     */
    public static synchronized JahiaCacheFactory getInstance()
    {
        if (m_instance == null) {
            m_instance = new JahiaCacheFactory();
        }
        return m_instance;
    } // end getInstance


   /**
    * Creates a new JahiaCache object
    *
    * @return the jahia cache
    */
    public JahiaCache createJahiaCache(String cacheName, String cachedesc, JahiaCacheIO cacheIO, int maxCachedObjects)
    {
        // a cache with similar name already exists!
        if (allCaches.get(cacheName)!=null)
        {
            JahiaConsole.println ("JahiaCacheFactory", "Huston, I think we have a problem : the cache "+cacheName+" is already defined!");
        }

        JahiaCache jCache = new JahiaCache(cacheName, cachedesc, cacheIO, maxCachedObjects);
        allCaches.put (cacheName, jCache);			// adds the cache to the hashtable
        return jCache;
    }

   /**
    * Creates a new JahiaSimpleCache object
    *
    * @return the jahia cache
    */
    public JahiaSimpleCache createJahiaSimpleCache(String cacheName, String cachedesc, int maxCachedObjects)
    {
        // a cache with similar name already exists!
        if (allCaches.get(cacheName)!=null)
        {
            JahiaConsole.println ("JahiaCacheFactory", "Huston, I think we have a problem : the cache "+cacheName+" is already defined!");
        }

        JahiaSimpleCache jCache = new JahiaSimpleCache(cacheName, cachedesc, maxCachedObjects);
        allCaches.put (cacheName, jCache);			// adds the cache to the hashtable
        return jCache;
    }

    /**
     * Returns a specific cache
     * @param cacheName name of the cache to retrieve from the factory.
     * @return Object returns an object because we store two different types
     * of object : JahiaCache or JahiaSimpleCache.
     * @todo FIXME we should really only store an common interface in here !!
     */
    public Object getCache(String cacheName) {
        return allCaches.get(cacheName);
    }

    /**
     * Returns an enumeration of all the cache names
     * @return an enumeration of String objects that contain the cache names.
     */
    public Enumeration getNames() {
        return allCaches.keys();
    }

} // end JahiaCacheFactory