/*
* 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.spi.scripting;
import java.lang.invoke.MethodHandles;
import java.util.Map;
import javax.script.ScriptEngine;
import javax.script.SimpleBindings;
import org.hibernate.validator.Incubating;
import org.hibernate.validator.internal.util.logging.Log;
import org.hibernate.validator.internal.util.logging.LoggerFactory;
A wrapper around JSR 223 ScriptEngine
s. This class is thread-safe. Author: Gunnar Morling, Kevin Pollet <kevin.pollet@serli.com> (C) 2011 SERLI Since: 6.0.3
/**
* A wrapper around JSR 223 {@link ScriptEngine}s. This class is thread-safe.
*
* @author Gunnar Morling
* @author Kevin Pollet <kevin.pollet@serli.com> (C) 2011 SERLI
* @since 6.0.3
*/
@Incubating
public class ScriptEngineScriptEvaluator implements ScriptEvaluator {
private static final Log LOG = LoggerFactory.make( MethodHandles.lookup() );
private final ScriptEngine engine;
Creates a new script executor.
Params: - engine – the engine to be wrapped
/**
* Creates a new script executor.
*
* @param engine the engine to be wrapped
*/
public ScriptEngineScriptEvaluator(ScriptEngine engine) {
this.engine = engine;
}
Executes the given script, using the given variable bindings. The execution of the script happens either synchronized or
unsynchronized, depending on the engine's threading abilities.
Params: - script – the script to be executed
- bindings – the bindings to be used
Throws: - ScriptEvaluationException – in case an error occurred during the script evaluation
Returns: the script's result
/**
* Executes the given script, using the given variable bindings. The execution of the script happens either synchronized or
* unsynchronized, depending on the engine's threading abilities.
*
* @param script the script to be executed
* @param bindings the bindings to be used
*
* @return the script's result
*
* @throws ScriptEvaluationException in case an error occurred during the script evaluation
*/
@Override
public Object evaluate(String script, Map<String, Object> bindings) throws ScriptEvaluationException {
if ( engineAllowsParallelAccessFromMultipleThreads() ) {
return doEvaluate( script, bindings );
}
else {
synchronized ( engine ) {
return doEvaluate( script, bindings );
}
}
}
private Object doEvaluate(String script, Map<String, Object> bindings) throws ScriptEvaluationException {
try {
return engine.eval( script, new SimpleBindings( bindings ) );
}
catch (Exception e) {
throw LOG.getErrorExecutingScriptException( script, e );
}
}
Checks whether the given engine is thread-safe or not.
Returns: true if the given engine is thread-safe, false otherwise.
/**
* Checks whether the given engine is thread-safe or not.
*
* @return true if the given engine is thread-safe, false otherwise.
*/
private boolean engineAllowsParallelAccessFromMultipleThreads() {
String threadingType = (String) engine.getFactory().getParameter( "THREADING" );
return "THREAD-ISOLATED".equals( threadingType ) || "STATELESS".equals( threadingType );
}
}