ASF_20_SRC_AUTO/src/blocks/session-fw/java/org/apache/cocoon/webapps/session/selection/MediaSelector.java

/*
 * Copyright 1999-2004 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.webapps.session.selection;

import java.util.Map;

import org.apache.avalon.framework.parameters.Parameters;
import org.apache.avalon.framework.service.ServiceException;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.avalon.framework.service.Serviceable;
import org.apache.avalon.framework.thread.ThreadSafe;
import org.apache.cocoon.selection.Selector;
import org.apache.cocoon.webapps.session.MediaManager;

/**
 *  This selector uses the media management.
 *
 * @author <a href="mailto:cziegeler@apache.org">Carsten Ziegeler</a>
 * @version CVS $Id: MediaSelector.java,v 1.3 2004/03/05 13:02:22 bdelacretaz Exp $
*/
public final class MediaSelector
implements Serviceable, Selector, ThreadSafe {

    private ServiceManager manager;

    /**
     * Selector
     */
    public boolean select (String expression, Map objectModel, Parameters parameters) {
        MediaManager mediaManager = null;
        boolean result;
        try {
            mediaManager = (MediaManager) this.manager.lookup( MediaManager.ROLE );
            result = mediaManager.testMedia(expression);
        } catch (Exception local) {
            // ignore me
            result = false;
        } finally {
            this.manager.release(mediaManager );
        }
        return result;
    }
    
    /* (non-Javadoc)
     * @see org.apache.avalon.framework.service.Serviceable#service(org.apache.avalon.framework.service.ServiceManager)
     */
    public void service(ServiceManager manager) throws ServiceException {
        this.manager = manager;
    }

}