org.objectstyle.cayenne.access.jdbc.SQLTemplateResourceManager Maven / Gradle / Ivy

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Cayenne Object Persistence Framework
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/* ====================================================================
 * 
 * The ObjectStyle Group Software License, version 1.1
 * ObjectStyle Group - http://objectstyle.org/
 * 
 * Copyright (c) 2002-2005, Andrei (Andrus) Adamchik and individual authors
 * of the software. All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 
 * 3. The end-user documentation included with the redistribution, if any,
 *    must include the following acknowlegement:
 *    "This product includes software developed by independent contributors
 *    and hosted on ObjectStyle Group web site (http://objectstyle.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 * 
 * 4. The names "ObjectStyle Group" and "Cayenne" must not be used to endorse
 *    or promote products derived from this software without prior written
 *    permission. For written permission, email
 *    "andrus at objectstyle dot org".
 * 
 * 5. Products derived from this software may not be called "ObjectStyle"
 *    or "Cayenne", nor may "ObjectStyle" or "Cayenne" appear in their
 *    names without prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE OBJECTSTYLE GROUP OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 * 
 * This software consists of voluntary contributions made by many
 * individuals and hosted on ObjectStyle Group web site.  For more
 * information on the ObjectStyle Group, please see
 * .
 */
package org.objectstyle.cayenne.access.jdbc;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.util.Map;

import org.apache.commons.collections.ExtendedProperties;
import org.apache.commons.collections.map.LRUMap;
import org.apache.velocity.Template;
import org.apache.velocity.exception.ParseErrorException;
import org.apache.velocity.exception.ResourceNotFoundException;
import org.apache.velocity.runtime.RuntimeServices;
import org.apache.velocity.runtime.resource.Resource;
import org.apache.velocity.runtime.resource.ResourceManager;
import org.apache.velocity.runtime.resource.loader.ResourceLoader;

/**
 * An implementation of the Velocity ResourceManager and ResourceLoader that
 * creates templates from in-memory Strings.
 * 
 * @author Andrei Adamchik
 * @since 1.1
 */
// class must be public since it is instantiated by Velocity via reflection.
public class SQLTemplateResourceManager
    extends ResourceLoader
    implements ResourceManager {

    protected Map templateCache;

    public void initialize(RuntimeServices rs) throws Exception {
        super.rsvc = rs;
        this.templateCache = new LRUMap(100);
    }

    public void clearCache() {
        templateCache.clear();
    }

    /**
     * Returns a Velocity Resource which is a Template for the given SQL.
     */
    public Resource getResource(String resourceName, int resourceType, String encoding)
        throws ResourceNotFoundException, ParseErrorException, Exception {

        synchronized (templateCache) {
            Template resource = (Template) templateCache.get(resourceName);

            if (resource == null) {
                resource = new Template();
                resource.setRuntimeServices(rsvc);
                resource.setResourceLoader(this);
                resource.setName(resourceName);
                resource.setEncoding(encoding);
                resource.process();

                templateCache.put(resourceName, resource);
            }

            return resource;
        }
    }

    public String getLoaderNameForResource(String resourceName) {
        return getClass().getName();
    }

    public long getLastModified(Resource resource) {
        return -1;
    }

    public InputStream getResourceStream(String source)
        throws ResourceNotFoundException {
        return new ByteArrayInputStream(source.getBytes());
    }

    public void init(ExtendedProperties configuration) {

    }

    public boolean isSourceModified(Resource resource) {
        return false;
    }
}