org.springframework.scripting.support.ScriptFactoryPostProcessor Maven / Gradle / Ivy
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* Copyright 2002-2007 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.support;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import net.sf.cglib.asm.Type;
import net.sf.cglib.core.Signature;
import net.sf.cglib.proxy.InterfaceMaker;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.aop.TargetSource;
import org.springframework.aop.framework.AopInfrastructureBean;
import org.springframework.aop.framework.ProxyFactory;
import org.springframework.aop.support.DelegatingIntroductionInterceptor;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.PropertyValue;
import org.springframework.beans.factory.BeanClassLoaderAware;
import org.springframework.beans.factory.BeanDefinitionStoreException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessorAdapter;
import org.springframework.beans.factory.support.AbstractBeanFactory;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.beans.factory.support.RootBeanDefinition;
import org.springframework.context.ResourceLoaderAware;
import org.springframework.core.Conventions;
import org.springframework.core.Ordered;
import org.springframework.core.io.DefaultResourceLoader;
import org.springframework.core.io.ResourceLoader;
import org.springframework.scripting.ScriptFactory;
import org.springframework.scripting.ScriptSource;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.ObjectUtils;
import org.springframework.util.StringUtils;
/**
* {@link org.springframework.beans.factory.config.BeanPostProcessor} that
* handles {@link org.springframework.scripting.ScriptFactory} definitions,
* replacing each factory with the actual scripted Java object generated by it.
*
* This is similar to the
* {@link org.springframework.beans.factory.FactoryBean} mechanism, but is
* specifically tailored for scripts and not built into Spring's core
* container itself but rather implemented as an extension.
*
*
NOTE: The most important characteristic of this post-processor
* is that constructor arguments are applied to the
* {@link org.springframework.scripting.ScriptFactory} instance
* while bean property values are applied to the generated scripted object.
* Typically, constructor arguments include a script source locator and
* potentially script interfaces, while bean property values include
* references and config values to inject into the scripted object itself.
*
*
The following {@link ScriptFactoryPostProcessor} will automatically
* be applied to the two
* {@link org.springframework.scripting.ScriptFactory} definitions below.
* At runtime, the actual scripted objects will be exposed for
* "bshMessenger" and "groovyMessenger", rather than the
* {@link org.springframework.scripting.ScriptFactory} instances. Both of
* those are supposed to be castable to the example's Messenger
* interfaces here.
*
*
<bean class="org.springframework.scripting.support.ScriptFactoryPostProcessor"/>
*
* <bean id="bshMessenger" class="org.springframework.scripting.bsh.BshScriptFactory">
* <constructor-arg value="classpath:mypackage/Messenger.bsh"/>
* <constructor-arg value="mypackage.Messenger"/>
* <property name="message" value="Hello World!"/>
* </bean>
*
* <bean id="groovyMessenger" class="org.springframework.scripting.bsh.GroovyScriptFactory">
* <constructor-arg value="classpath:mypackage/Messenger.groovy"/>
* <property name="message" value="Hello World!"/>
* </bean>
*
* NOTE: Please note that the above excerpt from a Spring
* XML bean definition file uses just the <bean/>-style syntax
* (in an effort to illustrate using the {@link ScriptFactoryPostProcessor} itself).
* In reality, you would never create a <bean/> definition for a
* {@link ScriptFactoryPostProcessor} explicitly; rather you would import the
* tags from the 'lang' namespace and simply create scripted
* beans using the tags in that namespace... as part of doing so, a
* {@link ScriptFactoryPostProcessor} will implicitly be created for you.
*
*
The Spring reference documentation contains numerous examples of using
* tags in the 'lang' namespace; by way of an example, find below
* a Groovy-backed bean defined using the 'lang:groovy' tag.
*
*
* <?xml version="1.0" encoding="UTF-8"?>
* <beans xmlns="http://www.springframework.org/schema/beans"
* xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
* xmlns:lang="http://www.springframework.org/schema/lang">
*
* <!-- this is the bean definition for the Groovy-backed Messenger implementation -->
* <lang:groovy id="messenger" script-source="classpath:Messenger.groovy">
* <lang:property name="message" value="I Can Do The Frug" />
* </lang:groovy>
*
* <!-- an otherwise normal bean that will be injected by the Groovy-backed Messenger -->
* <bean id="bookingService" class="x.y.DefaultBookingService">
* <property name="messenger" ref="messenger" />
* </bean>
*
* </beans>
*
* @author Juergen Hoeller
* @author Rob Harrop
* @author Rick Evans
* @since 2.0
*/
public class ScriptFactoryPostProcessor extends InstantiationAwareBeanPostProcessorAdapter
implements BeanClassLoaderAware, BeanFactoryAware, ResourceLoaderAware, DisposableBean, Ordered {
/**
* The {@link org.springframework.core.io.Resource}-style prefix that denotes
* an inline script.
* An inline script is a script that is defined right there in the (typically XML)
* configuration, as opposed to being defined in an external file.
*/
public static final String INLINE_SCRIPT_PREFIX = "inline:";
public static final String REFRESH_CHECK_DELAY_ATTRIBUTE =
Conventions.getQualifiedAttributeName(ScriptFactoryPostProcessor.class, "refreshCheckDelay");
private static final String SCRIPT_FACTORY_NAME_PREFIX = "scriptFactory.";
private static final String SCRIPTED_OBJECT_NAME_PREFIX = "scriptedObject.";
/** Logger available to subclasses */
protected final Log logger = LogFactory.getLog(getClass());
private long defaultRefreshCheckDelay = -1;
private ClassLoader beanClassLoader = ClassUtils.getDefaultClassLoader();
private AbstractBeanFactory beanFactory;
private ResourceLoader resourceLoader = new DefaultResourceLoader();
final DefaultListableBeanFactory scriptBeanFactory = new DefaultListableBeanFactory();
/** Map from bean name String to ScriptSource object */
private final Map scriptSourceCache = new HashMap();
/**
* Set the delay between refresh checks, in milliseconds.
* Default is -1, indicating no refresh checks at all.
*
Note that an actual refresh will only happen when
* the {@link org.springframework.scripting.ScriptSource} indicates
* that it has been modified.
* @see org.springframework.scripting.ScriptSource#isModified()
*/
public void setDefaultRefreshCheckDelay(long defaultRefreshCheckDelay) {
this.defaultRefreshCheckDelay = defaultRefreshCheckDelay;
}
public void setBeanClassLoader(ClassLoader classLoader) {
this.beanClassLoader = classLoader;
}
public void setBeanFactory(BeanFactory beanFactory) {
if (!(beanFactory instanceof AbstractBeanFactory)) {
throw new IllegalStateException(
"ScriptFactoryPostProcessor must run in AbstractBeanFactory, not in " + beanFactory);
}
this.beanFactory = (AbstractBeanFactory) beanFactory;
// Required so that references (up container hierarchies) are correctly resolved.
this.scriptBeanFactory.setParentBeanFactory(this.beanFactory);
// Required so that all BeanPostProcessors, Scopes, etc become available.
this.scriptBeanFactory.copyConfigurationFrom(this.beanFactory);
// Filter out BeanPostProcessors that are part of the AOP infrastructure,
// since those are only meant to apply to beans defined in the original factory.
for (Iterator it = this.scriptBeanFactory.getBeanPostProcessors().iterator(); it.hasNext();) {
BeanPostProcessor postProcessor = (BeanPostProcessor) it.next();
if (postProcessor instanceof AopInfrastructureBean) {
it.remove();
}
}
}
public void setResourceLoader(ResourceLoader resourceLoader) {
this.resourceLoader = resourceLoader;
}
public int getOrder() {
return Integer.MIN_VALUE;
}
public Class predictBeanType(Class beanClass, String beanName) {
// We only apply special treatment to ScriptFactory implementations here.
if (!ScriptFactory.class.isAssignableFrom(beanClass)) {
return null;
}
RootBeanDefinition bd = this.beanFactory.getMergedBeanDefinition(beanName);
String scriptFactoryBeanName = SCRIPT_FACTORY_NAME_PREFIX + beanName;
String scriptedObjectBeanName = SCRIPTED_OBJECT_NAME_PREFIX + beanName;
prepareScriptBeans(bd, scriptFactoryBeanName, scriptedObjectBeanName);
ScriptFactory scriptFactory =
(ScriptFactory) this.scriptBeanFactory.getBean(scriptFactoryBeanName, ScriptFactory.class);
ScriptSource scriptSource =
getScriptSource(scriptFactoryBeanName, scriptFactory.getScriptSourceLocator());
Class[] interfaces = scriptFactory.getScriptInterfaces();
Class scriptedType = null;
try {
scriptedType = scriptFactory.getScriptedObjectType(scriptSource);
}
catch (Exception ex) {
if (logger.isDebugEnabled()) {
logger.debug("Could not determine the scripted object type for script factory [" + scriptFactory + "]", ex);
}
}
if (scriptedType != null) {
return scriptedType;
}
else if (ObjectUtils.isEmpty(interfaces)) {
if (bd.isSingleton()) {
return this.scriptBeanFactory.getBean(scriptedObjectBeanName).getClass();
}
else {
return null;
}
}
else {
return (interfaces.length == 1 ? interfaces[0] : createCompositeInterface(interfaces));
}
}
public Object postProcessBeforeInstantiation(Class beanClass, String beanName) {
// We only apply special treatment to ScriptFactory implementations here.
if (!ScriptFactory.class.isAssignableFrom(beanClass)) {
return null;
}
RootBeanDefinition bd = this.beanFactory.getMergedBeanDefinition(beanName);
String scriptFactoryBeanName = SCRIPT_FACTORY_NAME_PREFIX + beanName;
String scriptedObjectBeanName = SCRIPTED_OBJECT_NAME_PREFIX + beanName;
prepareScriptBeans(bd, scriptFactoryBeanName, scriptedObjectBeanName);
long refreshCheckDelay = resolveRefreshCheckDelay(bd);
if (refreshCheckDelay >= 0) {
ScriptFactory scriptFactory =
(ScriptFactory) this.scriptBeanFactory.getBean(scriptFactoryBeanName, ScriptFactory.class);
ScriptSource scriptSource =
getScriptSource(scriptFactoryBeanName, scriptFactory.getScriptSourceLocator());
Class[] interfaces = scriptFactory.getScriptInterfaces();
RefreshableScriptTargetSource ts =
new RefreshableScriptTargetSource(this.scriptBeanFactory, scriptedObjectBeanName, scriptSource);
ts.setRefreshCheckDelay(refreshCheckDelay);
return createRefreshableProxy(ts, interfaces);
}
return this.scriptBeanFactory.getBean(scriptedObjectBeanName);
}
/**
* Prepare the script beans in the internal BeanFactory that this
* post-processor uses. Each original bean definition will be split
* into a ScriptFactory definition and a scripted object definition.
* @param bd the original bean definition in the main BeanFactory
* @param scriptFactoryBeanName the name of the internal ScriptFactory bean
* @param scriptedObjectBeanName the name of the internal scripted object bean
*/
protected void prepareScriptBeans(
RootBeanDefinition bd, String scriptFactoryBeanName, String scriptedObjectBeanName) {
// Avoid recreation of the script bean definition in case of a prototype.
synchronized (this.scriptBeanFactory) {
if (!this.scriptBeanFactory.containsBeanDefinition(scriptedObjectBeanName)) {
this.scriptBeanFactory.registerBeanDefinition(
scriptFactoryBeanName, createScriptFactoryBeanDefinition(bd));
ScriptFactory scriptFactory =
(ScriptFactory) this.scriptBeanFactory.getBean(scriptFactoryBeanName, ScriptFactory.class);
ScriptSource scriptSource =
getScriptSource(scriptFactoryBeanName, scriptFactory.getScriptSourceLocator());
Class[] interfaces = scriptFactory.getScriptInterfaces();
Class[] scriptedInterfaces = interfaces;
if (scriptFactory.requiresConfigInterface() && !bd.getPropertyValues().isEmpty()) {
PropertyValue[] pvs = bd.getPropertyValues().getPropertyValues();
Class configInterface = createConfigInterface(pvs, interfaces);
scriptedInterfaces = (Class[]) ObjectUtils.addObjectToArray(interfaces, configInterface);
}
RootBeanDefinition objectBd = createScriptedObjectBeanDefinition(
bd, scriptFactoryBeanName, scriptSource, scriptedInterfaces);
long refreshCheckDelay = resolveRefreshCheckDelay(bd);
if (refreshCheckDelay >= 0) {
objectBd.setSingleton(false);
}
this.scriptBeanFactory.registerBeanDefinition(scriptedObjectBeanName, objectBd);
}
}
}
/**
* Get the refresh check delay for the given {@link ScriptFactory} {@link BeanDefinition}.
* If the {@link BeanDefinition} has a
* {@link org.springframework.core.AttributeAccessor metadata attribute}
* under the key {@link #REFRESH_CHECK_DELAY_ATTRIBUTE} which is a valid {@link Number}
* type, then this value is used. Otherwise, the the {@link #defaultRefreshCheckDelay}
* value is used.
* @param beanDefinition the BeanDefinition to check
* @return the refresh check delay
*/
protected long resolveRefreshCheckDelay(BeanDefinition beanDefinition) {
long refreshCheckDelay = this.defaultRefreshCheckDelay;
Object attributeValue = beanDefinition.getAttribute(REFRESH_CHECK_DELAY_ATTRIBUTE);
if (attributeValue instanceof Number) {
refreshCheckDelay = ((Number) attributeValue).longValue();
}
else if (attributeValue instanceof String) {
refreshCheckDelay = Long.parseLong((String) attributeValue);
}
else if (attributeValue != null) {
throw new BeanDefinitionStoreException(
"Invalid refresh check delay attribute [" + REFRESH_CHECK_DELAY_ATTRIBUTE +
"] with value [" + attributeValue + "]: needs to be of type Number or String");
}
return refreshCheckDelay;
}
/**
* Create a ScriptFactory bean definition based on the given script definition,
* extracting only the definition data that is relevant for the ScriptFactory
* (that is, only bean class and constructor arguments).
* @param bd the full script bean definition
* @return the extracted ScriptFactory bean definition
* @see org.springframework.scripting.ScriptFactory
*/
protected RootBeanDefinition createScriptFactoryBeanDefinition(RootBeanDefinition bd) {
RootBeanDefinition scriptBd = new RootBeanDefinition();
scriptBd.setBeanClassName(bd.getBeanClassName());
scriptBd.getConstructorArgumentValues().addArgumentValues(bd.getConstructorArgumentValues());
return scriptBd;
}
/**
* Obtain a ScriptSource for the given bean, lazily creating it
* if not cached already.
* @param beanName the name of the scripted bean
* @param scriptSourceLocator the script source locator associated with the bean
* @return the corresponding ScriptSource instance
* @see #convertToScriptSource
*/
protected ScriptSource getScriptSource(String beanName, String scriptSourceLocator) {
synchronized (this.scriptSourceCache) {
ScriptSource scriptSource = (ScriptSource) this.scriptSourceCache.get(beanName);
if (scriptSource == null) {
scriptSource = convertToScriptSource(scriptSourceLocator, this.resourceLoader);
this.scriptSourceCache.put(beanName, scriptSource);
}
return scriptSource;
}
}
/**
* Convert the given script source locator to a ScriptSource instance.
*
By default, supported locators are Spring resource locations
* (such as "file:C:/myScript.bsh" or "classpath:myPackage/myScript.bsh")
* and inline scripts ("inline:myScriptText...").
* @param scriptSourceLocator the script source locator
* @param resourceLoader the ResourceLoader to use (if necessary)
* @return the ScriptSource instance
*/
protected ScriptSource convertToScriptSource(String scriptSourceLocator, ResourceLoader resourceLoader) {
if (scriptSourceLocator.startsWith(INLINE_SCRIPT_PREFIX)) {
return new StaticScriptSource(scriptSourceLocator.substring(INLINE_SCRIPT_PREFIX.length()));
}
else {
return new ResourceScriptSource(resourceLoader.getResource(scriptSourceLocator));
}
}
/**
* Create a config interface for the given bean property values.
*
This implementation creates the interface via CGLIB's InterfaceMaker,
* determining the property types from the given interfaces (as far as possible).
* @param pvs the bean property values to create a config interface for
* @param interfaces the interfaces to check against (might define
* getters corresponding to the setters we're supposed to generate)
* @return the config interface
* @see net.sf.cglib.proxy.InterfaceMaker
* @see org.springframework.beans.BeanUtils#findPropertyType
*/
protected Class createConfigInterface(PropertyValue[] pvs, Class[] interfaces) {
Assert.notEmpty(pvs, "Property values must not be empty");
InterfaceMaker maker = new InterfaceMaker();
for (int i = 0; i < pvs.length; i++) {
String propertyName = pvs[i].getName();
Class propertyType = BeanUtils.findPropertyType(propertyName, interfaces);
String setterName = "set" + StringUtils.capitalize(propertyName);
Signature signature = new Signature(setterName, Type.VOID_TYPE, new Type[] {Type.getType(propertyType)});
maker.add(signature, new Type[0]);
}
return maker.create();
}
/**
* Create a composite interface Class for the given interfaces,
* implementing the given interfaces in one single Class.
*
The default implementation builds a JDK proxy class
* for the given interfaces.
* @param interfaces the interfaces to merge
* @return the merged interface as Class
* @see java.lang.reflect.Proxy#getProxyClass
*/
protected Class createCompositeInterface(Class[] interfaces) {
return ClassUtils.createCompositeInterface(interfaces, this.beanClassLoader);
}
/**
* Create a bean definition for the scripted object, based on the given script
* definition, extracting the definition data that is relevant for the scripted
* object (that is, everything but bean class and constructor arguments).
* @param bd the full script bean definition
* @param scriptFactoryBeanName the name of the internal ScriptFactory bean
* @param scriptSource the ScriptSource for the scripted bean
* @param interfaces the interfaces that the scripted bean is supposed to implement
* @return the extracted ScriptFactory bean definition
* @see org.springframework.scripting.ScriptFactory#getScriptedObject
*/
protected RootBeanDefinition createScriptedObjectBeanDefinition(
RootBeanDefinition bd, String scriptFactoryBeanName, ScriptSource scriptSource, Class[] interfaces) {
RootBeanDefinition objectBd = new RootBeanDefinition(bd);
objectBd.setFactoryBeanName(scriptFactoryBeanName);
objectBd.setFactoryMethodName("getScriptedObject");
objectBd.getConstructorArgumentValues().clear();
objectBd.getConstructorArgumentValues().addIndexedArgumentValue(0, scriptSource);
objectBd.getConstructorArgumentValues().addIndexedArgumentValue(1, interfaces);
return objectBd;
}
/**
* Create a refreshable proxy for the given AOP TargetSource.
* @param ts the refreshable TargetSource
* @param interfaces the proxy interfaces (may be null to
* indicate proxying of all interfaces implemented by the target class)
* @return the generated proxy
* @see RefreshableScriptTargetSource
*/
protected Object createRefreshableProxy(TargetSource ts, Class[] interfaces) {
ProxyFactory proxyFactory = new ProxyFactory();
proxyFactory.setTargetSource(ts);
if (interfaces == null) {
interfaces = ClassUtils.getAllInterfacesForClass(ts.getTargetClass());
}
proxyFactory.setInterfaces(interfaces);
DelegatingIntroductionInterceptor introduction = new DelegatingIntroductionInterceptor(ts);
introduction.suppressInterface(TargetSource.class);
proxyFactory.addAdvice(introduction);
return proxyFactory.getProxy(this.beanClassLoader);
}
/**
* Destroy the inner bean factory (used for scripts) on shutdown.
*/
public void destroy() {
this.scriptBeanFactory.destroySingletons();
}
}