/*
* Hibernate Validator, declare and validate application constraints
*
* License: Apache License, Version 2.0
* See the license.txt file in the root directory or <http://www.apache.org/licenses/LICENSE-2.0>.
*/
package org.hibernate.validator.internal.engine.scripting;
import java.lang.invoke.MethodHandles;
import java.security.AccessController;
import java.security.PrivilegedAction;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import org.hibernate.validator.internal.util.logging.Log;
import org.hibernate.validator.internal.util.logging.LoggerFactory;
import org.hibernate.validator.internal.util.privilegedactions.GetClassLoader;
import org.hibernate.validator.spi.scripting.AbstractCachingScriptEvaluatorFactory;
import org.hibernate.validator.spi.scripting.ScriptEngineScriptEvaluator;
import org.hibernate.validator.spi.scripting.ScriptEvaluationException;
import org.hibernate.validator.spi.scripting.ScriptEvaluator;
Factory responsible for the creation of JSR 223 based ScriptEngineScriptEvaluator
s. This class is thread-safe. Author: Gunnar Morling, Kevin Pollet <kevin.pollet@serli.com> (C) 2011 SERLI, Marko Bekhta, Guillaume Smet
/**
* Factory responsible for the creation of JSR 223 based {@link ScriptEngineScriptEvaluator}s. This
* class is thread-safe.
*
* @author Gunnar Morling
* @author Kevin Pollet <kevin.pollet@serli.com> (C) 2011 SERLI
* @author Marko Bekhta
* @author Guillaume Smet
*/
public class DefaultScriptEvaluatorFactory extends AbstractCachingScriptEvaluatorFactory {
private static final Log LOG = LoggerFactory.make( MethodHandles.lookup() );
private ClassLoader classLoader;
private volatile ScriptEngineManager scriptEngineManager;
private volatile ScriptEngineManager threadContextClassLoaderScriptEngineManager;
public DefaultScriptEvaluatorFactory(ClassLoader externalClassLoader) {
classLoader = externalClassLoader == null ? DefaultScriptEvaluatorFactory.class.getClassLoader() : externalClassLoader;
}
@Override
public void clear() {
super.clear();
classLoader = null;
scriptEngineManager = null;
threadContextClassLoaderScriptEngineManager = null;
}
@Override
protected ScriptEvaluator createNewScriptEvaluator(String languageName) throws ScriptEvaluationException {
ScriptEngine engine = getScriptEngineManager().getEngineByName( languageName );
// fall back to the TCCL
if ( engine == null ) {
engine = getThreadContextClassLoaderScriptEngineManager().getEngineByName( languageName );
}
if ( engine == null ) {
throw LOG.getUnableToFindScriptEngineException( languageName );
}
return new ScriptEngineScriptEvaluator( engine );
}
private ScriptEngineManager getScriptEngineManager() {
if ( scriptEngineManager == null ) {
synchronized ( this ) {
if ( scriptEngineManager == null ) {
scriptEngineManager = new ScriptEngineManager( classLoader );
}
}
}
return scriptEngineManager;
}
private ScriptEngineManager getThreadContextClassLoaderScriptEngineManager() {
if ( threadContextClassLoaderScriptEngineManager == null ) {
synchronized ( this ) {
if ( threadContextClassLoaderScriptEngineManager == null ) {
threadContextClassLoaderScriptEngineManager = new ScriptEngineManager( run( GetClassLoader.fromContext() ) );
}
}
}
return threadContextClassLoaderScriptEngineManager;
}
Runs the given privileged action, using a privileged block if required.
NOTE: This must never be changed into a publicly available method to avoid execution of arbitrary
privileged actions within HV's protection domain.
/**
* Runs the given privileged action, using a privileged block if required.
* <p>
* <b>NOTE:</b> This must never be changed into a publicly available method to avoid execution of arbitrary
* privileged actions within HV's protection domain.
*/
private static <T> T run(PrivilegedAction<T> action) {
return System.getSecurityManager() != null ? AccessController.doPrivileged( action ) : action.run();
}
}