ingo@1127: /*
ingo@1127:  * Copyright (c) 2010 by Intevation GmbH
ingo@1127:  *
ingo@1127:  * This program is free software under the LGPL (>=v2.1)
ingo@1127:  * Read the file LGPL.txt coming with the software for details
ingo@1127:  * or visit http://www.gnu.org/licenses/ if it does not exist.
ingo@1127:  */
ingo@1127: 
tim@132: package de.intevation.gnv.geobackend.base.query.container;
tim@132: 
tim@132: import java.util.Properties;
tim@132: 
tim@132: import org.apache.log4j.Logger;
tim@132: 
tim@891: import de.intevation.gnv.geobackend.base.query.container.exception.QueryContainerException;
tim@891: 
tim@132: /**
sascha@893:  * Factoryclass to provide a singleton-Instance of an
tim@891:  * <code>QueryContainer</code>-Object
sascha@887:  * @author <a href="mailto:tim.englich@intevation.de">Tim Englich</a>
tim@132:  */
tim@132: public class QueryContainerFactory {
sascha@885: 
tim@132:     /**
tim@132:      * the logger, used to log exceptions and additonaly information
tim@132:      */
tim@132:     private static Logger log = Logger.getLogger(QueryContainerFactory.class);
tim@132: 
sascha@885: 
tim@132:     /**
tim@132:      * The singleton Instance of this Factory.
tim@132:      */
tim@132:     private static QueryContainerFactory instance = null;
tim@132: 
tim@132:     /**
tim@132:      * The ConnectionPool providing the Connections to the DatabaseBackends
tim@132:      */
tim@132:     private QueryContainer queryContainer = null;
tim@132: 
tim@132:     /**
tim@132:      * Basic-Constructor of this Class
tim@132:      */
tim@132:     private QueryContainerFactory() {
tim@132:         super();
tim@132:     }
tim@132: 
tim@132:     /**
tim@132:      * This Method provides an singleton Instance of this Class.
tim@132:      * @return an singleton Instance of this Class
tim@132:      */
sascha@541:     public static synchronized QueryContainerFactory getInstance(){
tim@132:         if (instance == null){
tim@132:             instance = new QueryContainerFactory();
tim@132:         }
tim@132:         return instance;
tim@132:     }
sascha@885: 
sascha@885: 
tim@132:     /**
tim@132:      * Getting the QueryContainer
tim@132:      * @return the QueryContainer
tim@132:      */
tim@132:     public QueryContainer getQueryContainer(){
tim@132:         return this.queryContainer;
tim@132:     }
tim@132: 
tim@132:     /**
tim@132:      * Initializes the QueryContainer.
tim@132:      * Should only be called once on system startup
tim@132:      * @param properties the Properties for the Individual Configuration of the QueryContainerbb
sascha@885:      * @throws QueryContainerException
tim@132:      */
tim@132:     public synchronized void initializeQueryContainer(Properties properties) throws QueryContainerException{
tim@132:         log.debug("ConnectionPoolFactory.initializeConnectionPool");
tim@132:         if (this.queryContainer == null){
tim@132:             this.queryContainer = new DefaultQueryContainer();
tim@132:             this.queryContainer.initialize(properties);
tim@132:         }else{
tim@132:             log.warn("ConnectionPool already initialized");
tim@132:         }
tim@132:     }
tim@132: 
tim@132:     /**
tim@132:      * Checks if the QueryContainer has already been initialized.
tim@132:      * @return true if the QueryContainer is initialized.
tim@132:      */
tim@132:     public boolean isInitialized(){
tim@132:         return this.queryContainer != null;
tim@132:     }
tim@132: }