enginesregistry.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 . . .
//

//
//  EnginesRegistry
//  EV      19.11.2000
//  AK      14.12.2000   temporary solution to catch getEngine() fault.
//  AK      14.12.2000   add the core engine.
//  AK      19.12.2000   add the managefield engine.
//	DJ				   07.02.2001	added logout engine.
//
//  init()
//  getEngine( name )
//

package org.jahia.registries;


import java.util.*;                         // HashTable
import org.jahia.utils.*;               // JahiaConsole


public class EnginesRegistry {

    private static  EnginesRegistry     theObject   = null;
    private         Hashtable           theRegistry;



    /***
        * constructor
        * EV    19.11.2000
        *
        */
    private EnginesRegistry()
    {
        JahiaConsole.println( "Registry", "***** Starting Engines Registry *****" );
    } // end constructor



    /***
        * getInstance
        * EV    19.11.2000
        *
        */
    public static synchronized EnginesRegistry getInstance()
    {
        if (theObject == null) {
            theObject = new EnginesRegistry();
        }
        return theObject;
    } // end getInstance



    /***
        * init
        * EV    19.11.2000
        * FIXME     : load registry from database ?
        * AK      14.12.2000 : add the core engine...
        * AK      19.12.2000 : add the managefield engine...
        *
        * called from init() method in Jahia servlet
        *
        */
    public void init()
    {
        ////////////////////////////////////////////////////////////////////////////////////////
        // FIXME -Fulco- :
        //   There is not error check in the lines below. An engine getInstance() method
        //   might return a null reference! Trying to add a null object in a hashtable will
        //   raise an NullPointerException !!
        ////////////////////////////////////////////////////////////////////////////////////////

        theRegistry = new Hashtable();
        theRegistry.put( "core",             org.jahia.engines.core.Core_Engine.getInstance()                           );
        theRegistry.put( "updatefield",      org.jahia.engines.updatefield.UpdateField_Engine.getInstance()             );
        theRegistry.put( "addcontainer",     org.jahia.engines.addcontainer.AddContainer_Engine.getInstance()           );
        theRegistry.put( "updatecontainer",  org.jahia.engines.updatecontainer.UpdateContainer_Engine.getInstance()     );
        theRegistry.put( "deletecontainer",  org.jahia.engines.deletecontainer.DeleteContainer_Engine.getInstance()     );
        theRegistry.put( "downloadtemplate", org.jahia.engines.downloadtemplate.DownloadTemplate_Engine.getInstance()   );
        theRegistry.put( "selectdatasource", org.jahia.engines.selectdatasource.SelectDataSource_Engine.getInstance()   );
        theRegistry.put( "datasourcefield",  org.jahia.engines.datasourcefield.DataSourceField_Engine.getInstance()     );
        theRegistry.put( "viewdatasourceid", org.jahia.engines.viewdatasourceid.ViewDataSourceID_Engine.getInstance()   );
        theRegistry.put( "search",           org.jahia.engines.search.Search_Engine.getInstance()                       );
        theRegistry.put( "login",            org.jahia.engines.login.Login_Engine.getInstance()                       	);
        theRegistry.put( "logout",           org.jahia.engines.logout.Logout_Engine.getInstance()                       );
        theRegistry.put( "filemanager",      org.jahia.engines.filemanager.Filemanager_Engine.getInstance()             );
        theRegistry.put( "pageproperties",   org.jahia.engines.pages.PageProperties_Engine.getInstance()                );
        theRegistry.put( "containerlistproperties",   org.jahia.engines.containerlistproperties.ContainerListProperties_Engine.getInstance() );
        theRegistry.put( "sitemap",          org.jahia.engines.sitemap.SiteMap_Engine.getInstance()                     );
        theRegistry.put( "applications",     org.jahia.engines.applications.Applications_Engine.getInstance()           );
        theRegistry.put( "copytree",         org.jahia.engines.copytree.CopyTree_Engine.getInstance()                   );
        theRegistry.put( "sites",            org.jahia.engines.sites.Sites_Engine.getInstance()                   		);
        theRegistry.put( "template",         org.jahia.engines.template.Template_Engine.getInstance()              		);
        theRegistry.put( "selectUG",      org.jahia.engines.users.SelectUG_Engine.getInstance()                          );
    } // end init



    /***
        * getEngine
        * EV    19.11.2000
        * AK      14.12.2000 : temporary solution to catch getEngine() fault.
        *                                 if the engine doesn't exist, core is selected...
        *
        */
    public Object getEngine( String engineName )
    {
        Object engineToGet = theRegistry.get( engineName );
        if(engineToGet == null)
        {
            engineToGet = theRegistry.get( "core" );
        }
        return engineToGet;
    } // end getEngine


} // end EnginesRegistry