/**
* This file is part of Jahia, next-generation open source CMS:
* Jahia's next-generation, open source CMS stems from a widely acknowledged vision
* of enterprise application convergence - web, search, document, social and portal -
* unified by the simplicity of web content management.
*
* For more information, please visit http://www.jahia.com.
*
* Copyright (C) 2002-2011 Jahia Solutions Group SA. All rights reserved.
*
* This program 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 2
* of the License, or (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* As a special exception to the terms and conditions of version 2.0 of
* the GPL (or any later version), you may redistribute this Program in connection
* with Free/Libre and Open Source Software ("FLOSS") applications as described
* in Jahia's FLOSS exception. You should have received a copy of the text
* describing the FLOSS exception, and it is also available here:
* http://www.jahia.com/license
*
* Commercial and Supported Versions of the program (dual licensing):
* alternatively, commercial and supported versions of the program may be used
* in accordance with the terms and conditions contained in a separate
* written agreement between you and Jahia Solutions Group SA.
*
* If you are unsure which license is appropriate for your use,
* please contact the sales department at sales@jahia.com.
*/
package org.jahia.utils;
import org.springframework.beans.factory.InitializingBean;
import javax.script.ScriptContext;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Properties;
/**
* ScriptEngine provider class.
*
* @author rincevent
* @since JAHIA 6.5
* Created : 27/01/11
*/
public class ScriptEngineUtils implements InitializingBean {
private static ScriptEngineUtils instance;
public static ScriptEngineUtils getInstance() {
if (instance == null) {
synchronized (ScriptEngineUtils.class) {
if (instance == null) {
instance = new ScriptEngineUtils();
}
}
}
return instance;
}
private Map<String, ScriptEngine> scriptEngineByExtensionCache;
private Map<String, ScriptEngine> scriptEngineByNameCache;
private ScriptEngineManager scriptEngineManager;
public void afterPropertiesSet() throws Exception {
scriptEngineManager = new ScriptEngineManager();
scriptEngineByExtensionCache = new LinkedHashMap<String, ScriptEngine>(3);
scriptEngineByNameCache = new LinkedHashMap<String, ScriptEngine>(3);
}
/**
* Returns an instance of a {@link ScriptEngine} by its name.
* @param name the name of the script engine to look for
* @return an instance of a {@link ScriptEngine} by its name
* @throws ScriptException in case of a script engine initialization error
*/
public ScriptEngine getEngineByName(String name) throws ScriptException {
ScriptEngine scriptEngine = scriptEngineByNameCache.get(name);
if (scriptEngine == null) {
scriptEngine = scriptEngineManager.getEngineByName(name);
if (scriptEngine == null) {
throw new ScriptException("Script engine not found for name :" + name);
}
initEngine(scriptEngine);
scriptEngineByNameCache.put(name, scriptEngine);
}
return scriptEngine;
}
private void initEngine(ScriptEngine engine) {
if (engine.getFactory().getNames().contains("velocity")) {
Properties velocityProperties = new Properties();
velocityProperties.setProperty("runtime.log.logsystem.log4j.logger", "velocity");
engine.getContext().setAttribute("com.sun.script.velocity.properties", velocityProperties, ScriptContext.GLOBAL_SCOPE);
}
}
/**
* Returns an instance of a {@link ScriptEngine} by its file extension.
* @param extension the extension of the script engine to look for
* @return an instance of a {@link ScriptEngine} by its name
* @throws ScriptException in case of a script engine initialization error
*/
public ScriptEngine scriptEngine(String extension) throws ScriptException {
ScriptEngine scriptEngine = scriptEngineByExtensionCache.get(extension);
if (scriptEngine == null) {
scriptEngine = scriptEngineManager.getEngineByExtension(extension);
if (scriptEngine == null) {
throw new ScriptException("Script engine not found for extension:" + extension);
}
initEngine(scriptEngine);
scriptEngineByExtensionCache.put(extension, scriptEngine);
}
return scriptEngine;
}
}