tim@132: package de.intevation.gnv.geobackend.base.query;
tim@132: 
ingo@1122: import de.intevation.gnv.geobackend.config.Configuration;
ingo@1122: 
tim@132: import org.apache.log4j.Logger;
tim@132: 
tim@132: /**
sascha@887:  * @author <a href="mailto:tim.englich@intevation.de">Tim Englich</a>
tim@132:  *
tim@132:  */
tim@132: public class QueryExecutorFactory {
sascha@541: 
sascha@541:     public static final String QUERY_EXECUTOR_FACTORY = "query.executor.factory";
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(QueryExecutorFactory.class);
tim@132: 
sascha@885: 
tim@132:     /**
tim@132:      * The singleton Instance of this Factory.
tim@132:      */
tim@132:     private static QueryExecutorFactory instance = null;
tim@132: 
tim@132:     /**
tim@132:      * Basic-Constructor of this Class
tim@132:      */
sascha@541:     public QueryExecutorFactory() {
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 QueryExecutorFactory getInstance(){
sascha@541:         if (instance == null) {
ingo@1122:             Configuration config = Configuration.getInstance();
ingo@1122: 
ingo@1122:             if (config.isCacheEnabled()) {
ingo@1122:                 final QueryExecutorFactory factory =
ingo@1122:                     new CachingQueryExecutorFactory();
ingo@1122:                 Runtime.getRuntime().addShutdownHook(new Thread() {
ingo@1122:                     @Override
ingo@1122:                     public void run() {
ingo@1122:                         factory.shutdown();
ingo@1122:                     }
ingo@1122:                 });
ingo@1122:                 return instance = factory;
sascha@541:             }
sascha@541: 
tim@132:             instance = new QueryExecutorFactory();
tim@132:         }
tim@132:         return instance;
tim@132:     }
sascha@542: 
sascha@542:     public void shutdown() {
sascha@542:     }
sascha@885: 
tim@132:     /**
tim@132:      * Getting the QueryExecutor
tim@132:      * @return the QueryExecutor
tim@132:      */
tim@132:     public QueryExecutor getQueryExecutor(){
tim@132:         return new DefaultQueryExceutor();
tim@132:     }
tim@132: }