org.springframework.scripting.config.ScriptBeanDefinitionParser Maven / Gradle / Ivy
/*
* 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.config;
import java.util.List;
import org.w3c.dom.Element;
import org.springframework.beans.factory.config.ConstructorArgumentValues;
import org.springframework.beans.factory.config.RuntimeBeanReference;
import org.springframework.beans.factory.support.AbstractBeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.RootBeanDefinition;
import org.springframework.beans.factory.xml.AbstractBeanDefinitionParser;
import org.springframework.beans.factory.xml.ParserContext;
import org.springframework.beans.factory.xml.XmlReaderContext;
import org.springframework.scripting.support.ScriptFactoryPostProcessor;
import org.springframework.util.StringUtils;
import org.springframework.util.xml.DomUtils;
/**
* BeanDefinitionParser implementation for the '<lang:groovy/>',
* '<lang:jruby/>' and '<lang:bsh/>' tags.
* Allows for objects written using dynamic languages to be easily exposed with
* the {@link org.springframework.beans.factory.BeanFactory}.
*
* The script for each object can be specified either as a reference to the Resource
* containing it (using the 'script-source' attribute) or inline in the XML configuration
* itself (using the 'inline-script' attribute.
*
*
By default, dynamic objects created with these tags are not refreshable.
* To enable refreshing, specify the refresh check delay for each object (in milliseconds) using the
* 'refresh-check-delay' attribute.
*
* @author Rob Harrop
* @author Rod Johnson
* @since 2.0
*/
class ScriptBeanDefinitionParser extends AbstractBeanDefinitionParser {
/**
* The unique name under which the internally managed {@link ScriptFactoryPostProcessor} is
* registered in the {@link BeanDefinitionRegistry}.
*/
private static final String SCRIPT_FACTORY_POST_PROCESSOR_BEAN_NAME = ".scriptFactoryPostProcessor";
private static final String SCRIPT_SOURCE_ATTRIBUTE = "script-source";
private static final String INLINE_SCRIPT_ELEMENT = "inline-script";
private static final String SCOPE_ATTRIBUTE = "scope";
private static final String SCRIPT_INTERFACES_ATTRIBUTE = "script-interfaces";
private static final String REFRESH_CHECK_DELAY_ATTRIBUTE = "refresh-check-delay";
private static final String CUSTOMIZER_REF_ATTRIBUTE = "customizer-ref";
/**
* The {@link org.springframework.scripting.ScriptFactory} class that this
* parser instance will create bean definitions for.
*/
private final String scriptFactoryClassName;
/**
* Create a new instance of this parser, creating bean definitions for the
* supplied {@link org.springframework.scripting.ScriptFactory} class.
* @param scriptFactoryClassName the ScriptFactory class to operate on
*/
public ScriptBeanDefinitionParser(String scriptFactoryClassName) {
this.scriptFactoryClassName = scriptFactoryClassName;
}
/**
* Parses the dynamic object element and returns the resulting bean definition.
* Registers a {@link ScriptFactoryPostProcessor} if needed.
*/
protected AbstractBeanDefinition parseInternal(Element element, ParserContext parserContext) {
// Resolve the script source.
String value = resolveScriptSource(element, parserContext.getReaderContext());
if (value == null) {
return null;
}
// Set up infrastructure.
registerScriptFactoryPostProcessorIfNecessary(parserContext.getRegistry());
// Create script factory bean definition.
RootBeanDefinition beanDefinition = new RootBeanDefinition();
beanDefinition.setBeanClassName(this.scriptFactoryClassName);
beanDefinition.setSource(parserContext.extractSource(element));
// Determine bean scope.
String scope = element.getAttribute(SCOPE_ATTRIBUTE);
if (StringUtils.hasLength(scope)) {
beanDefinition.setScope(scope);
}
// Attach any refresh metadata.
String refreshCheckDelay = element.getAttribute(REFRESH_CHECK_DELAY_ATTRIBUTE);
if (StringUtils.hasText(refreshCheckDelay)) {
beanDefinition.setAttribute(
ScriptFactoryPostProcessor.REFRESH_CHECK_DELAY_ATTRIBUTE, new Long(refreshCheckDelay));
}
// Add constructor arguments.
ConstructorArgumentValues cav = beanDefinition.getConstructorArgumentValues();
int constructorArgNum = 0;
cav.addIndexedArgumentValue(constructorArgNum++, value);
if (element.hasAttribute(SCRIPT_INTERFACES_ATTRIBUTE)) {
cav.addIndexedArgumentValue(constructorArgNum++, element.getAttribute(SCRIPT_INTERFACES_ATTRIBUTE));
}
// This is used for Groovy. It's a bean reference to a customizer bean.
if (element.hasAttribute(CUSTOMIZER_REF_ATTRIBUTE)) {
String customizerBeanName = element.getAttribute(CUSTOMIZER_REF_ATTRIBUTE);
cav.addIndexedArgumentValue(constructorArgNum++, new RuntimeBeanReference(customizerBeanName));
}
// Add any property definitions that need adding.
parserContext.getDelegate().parsePropertyElements(element, beanDefinition);
return beanDefinition;
}
/**
* Resolves the script source from either the 'script-source' attribute or
* the 'inline-script' element. Logs and {@link XmlReaderContext#error} and
* returns null if neither or both of these values are specified.
*/
private String resolveScriptSource(Element element, XmlReaderContext readerContext) {
boolean hasScriptSource = element.hasAttribute(SCRIPT_SOURCE_ATTRIBUTE);
List elements = DomUtils.getChildElementsByTagName(element, INLINE_SCRIPT_ELEMENT);
if (hasScriptSource && !elements.isEmpty()) {
readerContext.error("Only one of 'script-source' and 'inline-script' should be specified.", element);
return null;
}
else if (hasScriptSource) {
return element.getAttribute(SCRIPT_SOURCE_ATTRIBUTE);
}
else if (!elements.isEmpty()) {
Element inlineElement = (Element) elements.get(0);
return "inline:" + DomUtils.getTextValue(inlineElement);
}
else {
readerContext.error("Must specify either 'script-source' or 'inline-script'.", element);
return null;
}
}
/**
* Registers a {@link ScriptFactoryPostProcessor} bean definition in the supplied
* {@link BeanDefinitionRegistry} if the {@link ScriptFactoryPostProcessor} hasn't
* already been registered.
*/
private static void registerScriptFactoryPostProcessorIfNecessary(BeanDefinitionRegistry registry) {
if (!registry.containsBeanDefinition(SCRIPT_FACTORY_POST_PROCESSOR_BEAN_NAME)) {
RootBeanDefinition beanDefinition = new RootBeanDefinition(ScriptFactoryPostProcessor.class);
registry.registerBeanDefinition(SCRIPT_FACTORY_POST_PROCESSOR_BEAN_NAME, beanDefinition);
}
}
}