org.mycore.common.xsl.MCRXSLTransformerFactory Maven / Gradle / Ivy
/*
* This file is part of *** M y C o R e ***
* See http://www.mycore.de/ for details.
*
* MyCoRe is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* MyCoRe is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with MyCoRe. If not, see .
*/
package org.mycore.common.xsl;
import java.io.IOException;
import javax.xml.transform.Templates;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import org.mycore.common.MCRCache;
import org.mycore.common.config.MCRConfiguration2;
/**
* Returns a Transformer for a given XSL source, providing caching of
* already compiled XSL stylesheets. The cache size can be set via
* MCR.LayoutService.XSLCacheSize (default is 200).
*
* @author Frank L\u00FCtzenkirchen
*/
public class MCRXSLTransformerFactory {
/** A cache of already compiled stylesheets */
private static MCRCache cache;
private static long checkPeriod;
static {
int cacheSize = MCRConfiguration2.getInt("MCR.LayoutService.XSLCacheSize").orElse(200);
checkPeriod = MCRConfiguration2.getLong("MCR.LayoutService.LastModifiedCheckPeriod").orElse(10000l);
cache = new MCRCache<>(cacheSize, MCRXSLTransformerFactory.class.getName());
}
/** Returns the compiled XSL templates cached for the given source, if it is up-to-date.
* @throws IOException */
private static Templates getCachedTemplates(MCRTemplatesSource source) throws IOException {
String key = source.getKey();
return cache.getIfUpToDate(key, source.getModifiedHandle(checkPeriod));
}
/** Compiles the given XSL source, and caches the result */
private static Templates compileTemplates(MCRTemplatesSource source) {
Templates templates = MCRTemplatesCompiler.compileTemplates(source);
cache.put(source.getKey(), templates);
return templates;
}
/** Returns a transformer for the given XSL source
*/
public static Transformer getTransformer(MCRTemplatesSource source)
throws IOException, TransformerConfigurationException {
Templates templates = getCachedTemplates(source);
if (templates == null) {
templates = compileTemplates(source);
}
return MCRTemplatesCompiler.getTransformer(templates);
}
}