/*
* Copyright 2002-2008 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.scripting.groovy;
import java.io.IOException;
import groovy.lang.GroovyClassLoader;
import groovy.lang.GroovyObject;
import groovy.lang.MetaClass;
import groovy.lang.Script;
import org.codehaus.groovy.control.CompilationFailedException;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanClassLoaderAware;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.scripting.ScriptCompilationException;
import org.springframework.scripting.ScriptFactory;
import org.springframework.scripting.ScriptSource;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
/**
* {@link org.springframework.scripting.ScriptFactory} implementation
* for a Groovy script.
*
* <p>Typically used in combination with a
* {@link org.springframework.scripting.support.ScriptFactoryPostProcessor};
* see the latter's javadoc} for a configuration example.
*
* @author Juergen Hoeller
* @author Rob Harrop
* @author Rod Johnson
* @since 2.0
* @see groovy.lang.GroovyClassLoader
* @see org.springframework.scripting.support.ScriptFactoryPostProcessor
*/
public class GroovyScriptFactory implements ScriptFactory, BeanFactoryAware, BeanClassLoaderAware {
private final String scriptSourceLocator;
private final GroovyObjectCustomizer groovyObjectCustomizer;
private GroovyClassLoader groovyClassLoader;
private Class scriptClass;
private Class scriptResultClass;
private CachedResultHolder cachedResult;
private final Object scriptClassMonitor = new Object();
private boolean wasModifiedForTypeCheck = false;
/**
* Create a new GroovyScriptFactory for the given script source.
* <p>We don't need to specify script interfaces here, since
* a Groovy script defines its Java interfaces itself.
* @param scriptSourceLocator a locator that points to the source of the script.
* Interpreted by the post-processor that actually creates the script.
*/
public GroovyScriptFactory(String scriptSourceLocator) {
this(scriptSourceLocator, null);
}
/**
* Create a new GroovyScriptFactory for the given script source,
* specifying a strategy interface that can create a custom MetaClass
* to supply missing methods and otherwise change the behavior of the object.
* <p>We don't need to specify script interfaces here, since
* a Groovy script defines its Java interfaces itself.
* @param scriptSourceLocator a locator that points to the source of the script.
* Interpreted by the post-processor that actually creates the script.
* @param groovyObjectCustomizer a customizer that can set a custom metaclass
* or make other changes to the GroovyObject created by this factory
* (may be <code>null</code>)
*/
public GroovyScriptFactory(String scriptSourceLocator, GroovyObjectCustomizer groovyObjectCustomizer) {
Assert.hasText(scriptSourceLocator, "'scriptSourceLocator' must not be empty");
this.scriptSourceLocator = scriptSourceLocator;
this.groovyObjectCustomizer = groovyObjectCustomizer;
}
public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
if (beanFactory instanceof ConfigurableListableBeanFactory) {
((ConfigurableListableBeanFactory) beanFactory).ignoreDependencyType(MetaClass.class);
}
}
public void setBeanClassLoader(ClassLoader classLoader) {
this.groovyClassLoader = new GroovyClassLoader(classLoader);
}
/**
* Return the GroovyClassLoader used by this script factory.
*/
public GroovyClassLoader getGroovyClassLoader() {
synchronized (this.scriptClassMonitor) {
if (this.groovyClassLoader == null) {
this.groovyClassLoader = new GroovyClassLoader(ClassUtils.getDefaultClassLoader());
}
return this.groovyClassLoader;
}
}
public String getScriptSourceLocator() {
return this.scriptSourceLocator;
}
/**
* Groovy scripts determine their interfaces themselves,
* hence we don't need to explicitly expose interfaces here.
* @return <code>null</code> always
*/
public Class[] getScriptInterfaces() {
return null;
}
/**
* Groovy scripts do not need a config interface,
* since they expose their setters as public methods.
*/
public boolean requiresConfigInterface() {
return false;
}
/**
* Loads and parses the Groovy script via the GroovyClassLoader.
* @see groovy.lang.GroovyClassLoader
*/
public Object getScriptedObject(ScriptSource scriptSource, Class[] actualInterfaces)
throws IOException, ScriptCompilationException {
try {
Class scriptClassToExecute = null;
synchronized (this.scriptClassMonitor) {
this.wasModifiedForTypeCheck = false;
if (this.cachedResult != null) {
Object result = this.cachedResult.object;
this.cachedResult = null;
return result;
}
if (this.scriptClass == null || scriptSource.isModified()) {
// New script content...
this.scriptClass = getGroovyClassLoader().parseClass(
scriptSource.getScriptAsString(), scriptSource.suggestedClassName());
if (Script.class.isAssignableFrom(this.scriptClass)) {
// A Groovy script, probably creating an instance: let's execute it.
Object result = executeScript(scriptSource, this.scriptClass);
this.scriptResultClass = (result != null ? result.getClass() : null);
return result;
}
else {
this.scriptResultClass = this.scriptClass;
}
}
scriptClassToExecute = this.scriptClass;
}
// Process re-execution outside of the synchronized block.
return executeScript(scriptSource, scriptClassToExecute);
}
catch (CompilationFailedException ex) {
throw new ScriptCompilationException(scriptSource, ex);
}
}
public Class getScriptedObjectType(ScriptSource scriptSource)
throws IOException, ScriptCompilationException {
try {
synchronized (this.scriptClassMonitor) {
if (this.scriptClass == null || scriptSource.isModified()) {
// New script content...
this.wasModifiedForTypeCheck = true;
this.scriptClass = getGroovyClassLoader().parseClass(
scriptSource.getScriptAsString(), scriptSource.suggestedClassName());
if (Script.class.isAssignableFrom(this.scriptClass)) {
// A Groovy script, probably creating an instance: let's execute it.
Object result = executeScript(scriptSource, this.scriptClass);
this.scriptResultClass = (result != null ? result.getClass() : null);
this.cachedResult = new CachedResultHolder(result);
}
else {
this.scriptResultClass = this.scriptClass;
}
}
return this.scriptResultClass;
}
}
catch (CompilationFailedException ex) {
throw new ScriptCompilationException(scriptSource, ex);
}
}
public boolean requiresScriptedObjectRefresh(ScriptSource scriptSource) {
synchronized (this.scriptClassMonitor) {
return (scriptSource.isModified() || this.wasModifiedForTypeCheck);
}
}
/**
* Instantiate the given Groovy script class and run it if necessary.
* @param scriptSource the source for the underlying script
* @param scriptClass the Groovy script class
* @return the result object (either an instance of the script class
* or the result of running the script instance)
* @throws ScriptCompilationException in case of instantiation failure
*/
protected Object executeScript(ScriptSource scriptSource, Class scriptClass) throws ScriptCompilationException {
try {
GroovyObject goo = (GroovyObject) scriptClass.newInstance();
if (this.groovyObjectCustomizer != null) {
// Allow metaclass and other customization.
this.groovyObjectCustomizer.customize(goo);
}
if (goo instanceof Script) {
// A Groovy script, probably creating an instance: let's execute it.
return ((Script) goo).run();
}
else {
// An instance of the scripted class: let's return it as-is.
return goo;
}
}
catch (InstantiationException ex) {
throw new ScriptCompilationException(
scriptSource, "Could not instantiate Groovy script class: " + scriptClass.getName(), ex);
}
catch (IllegalAccessException ex) {
throw new ScriptCompilationException(
scriptSource, "Could not access Groovy script constructor: " + scriptClass.getName(), ex);
}
}
public String toString() {
return "GroovyScriptFactory: script source locator [" + this.scriptSourceLocator + "]";
}
/**
* Wrapper that holds a temporarily cached result object.
*/
private static class CachedResultHolder {
public final Object object;
public CachedResultHolder(Object object) {
this.object = object;
}
}
}