ASF_20_SRC_AUTO/src/blocks/ojb/java/org/apache/cocoon/ojb/odmg/components/OdmgImplementationImpl.java

/*
 * Copyright 1999-2002,2004 The Apache Software Foundation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.cocoon.ojb.odmg.components;

import java.util.Hashtable;
import java.util.Iterator;
import java.util.Set;

import org.apache.avalon.framework.activity.Disposable;
import org.apache.avalon.framework.activity.Initializable;
import org.apache.avalon.framework.configuration.Configurable;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.thread.ThreadSafe;
import org.apache.cocoon.ojb.components.AbstractOjbImpl;
import org.apache.ojb.odmg.OJB;
import org.odmg.Database;
import org.odmg.Implementation;
import org.odmg.ODMGException;


/**
 * Implementation of the OdmgImplementation. Create a ODMG Implementation and store it for future use
 *
 * @author <a href="mailto:giacomo@apache.org">Giacomo Pati</a>
 * @version CVS $Id: OdmgImplementationImpl.java,v 1.3 2004/03/05 13:02:02 bdelacretaz Exp $
 */
public class OdmgImplementationImpl
    extends AbstractOjbImpl
    implements OdmgImplementation, Configurable, Initializable, Disposable, ThreadSafe {

    private final static String DEFAULT_CONNECTION ="default";
    private final static int DEFAULT_MODE = Database.OPEN_READ_WRITE;
    private Implementation odmg;
    
    private Hashtable databases = new Hashtable();
    
    /*  (non-Javadoc)
     * @see org.apache.avalon.framework.configuration.Configurable#configure(org.apache.avalon.framework.configuration.Configuration)
     */
    public void configure(Configuration myconf)
        throws ConfigurationException {
        if (this.getLogger().isDebugEnabled()) {
            this.getLogger().debug("OJB-ODMG: configuration");
        }
    }

    /*  (non-Javadoc)
     * @see org.apache.avalon.framework.activity.Disposable#dispose()
     */
    public void dispose() {
        super.dispose();
        synchronized(this.databases) {
            final Set keys = this.databases.keySet();
            for( Iterator i = keys.iterator(); i.hasNext(); )
            {
                final Database db = (Database)i.next();
                try
                {
                    db.close();
                }
                catch( final ODMGException e) {
                    getLogger().error( "OJB-ODMG: Cannot close Database", e);
                }
                i.remove();
            }
        }
        if (this.getLogger().isDebugEnabled()) {
            this.getLogger().debug("OJB-ODMG: Disposed OK!");
        }
    }

    /* (non-Javadoc)
     * @see org.apache.avalon.framework.activity.Initializable#initialize()
     */
    public void initialize()
        throws Exception {
        super.initialize();
        try {
            // Get the Implementation
            this.odmg = OJB.getInstance();
            
            if (this.getLogger().isDebugEnabled()) {
                this.getLogger().debug("OJB-ODMG: Started OK!");
            }
        } catch (Throwable t) {
            if (this.getLogger().isFatalErrorEnabled()) {
                this.getLogger().fatalError("OJB-ODMG: Started failed: Cannot get an ODMG Implementation.", t);
            }
        }
    }

    /* (non-Javadoc)
     * @see org.apache.cocoon.ojb.odmg.components.Odmg#getInstance()
     */
    public Implementation getInstance() throws ODMGException {
        Database db = (Database)this.databases.get( DEFAULT_CONNECTION );
        if(null == db ) {
            db = this.odmg.newDatabase();
            db.open(DEFAULT_CONNECTION, DEFAULT_MODE);
            synchronized (this.databases) {
                this.databases.put( DEFAULT_CONNECTION + DEFAULT_MODE, db );
            }
        }
        return this.odmg;
    }

    /* (non-Javadoc)
     * @see org.apache.cocoon.ojb.odmg.components.Odmg#getInstance(java.lang.String, int)
     */
    public Implementation getInstance(String connection, int mode) throws ODMGException {
        Database db = (Database)this.databases.get( connection + mode);
        if(null == db ) {
            db = this.odmg.newDatabase();
            db.open(connection, mode);
            synchronized (this.databases) {
                this.databases.put( connection + mode, db );
            }
        }
        return this.odmg;
    }

    /* (non-Javadoc)
     * @see org.apache.cocoon.ojb.odmg.components.Odmg#getInstance(java.lang.String)
     */
    public Implementation getInstance(String connection) throws ODMGException {
        Database db = (Database)this.databases.get( connection + DEFAULT_MODE);
        if(null == db ) {
            db = this.odmg.newDatabase();
            db.open(connection, DEFAULT_MODE);
            synchronized (this.databases) {
                this.databases.put( connection + DEFAULT_MODE, db );
            }
        }
        return this.odmg;
    }
    /* (non-Javadoc)
     * @see org.apache.cocoon.ojb.odmg.components.OdmgImplementation#getInstance(int)
     */
    public Implementation getInstance( int mode ) throws ODMGException 
    {
        Database db = (Database)this.databases.get( DEFAULT_CONNECTION+ mode);
        if(null == db ) {
            db = this.odmg.newDatabase();
            db.open(DEFAULT_CONNECTION, mode);
            synchronized (this.databases) {
                this.databases.put( DEFAULT_CONNECTION+ mode, db );
            }
        }
        return this.odmg;
    }
}