org.springframework.beans.factory.xml.AbstractSingleBeanDefinitionParser 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.beans.factory.xml;
import org.w3c.dom.Element;
import org.springframework.beans.factory.support.AbstractBeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.util.Assert;
/**
* Base class for those {@link BeanDefinitionParser} implementations that
* need to parse and define just a single BeanDefinition.
*
* Extend this parser class when you want to create a single bean definition
* from an arbitrarily complex XML element. You may wish to consider extending
* the {@link AbstractSimpleBeanDefinitionParser} when you want to create a
* single bean definition from a relatively simple custom XML element.
*
*
The resulting BeanDefinition will be automatically registered
* with the {@link org.springframework.beans.factory.support.BeanDefinitionRegistry}.
* Your job simply is to {@link #doParse parse} the custom XML {@link Element}
* into a single BeanDefinition.
*
* @author Rob Harrop
* @author Juergen Hoeller
* @author Rick Evans
* @since 2.0
*/
public abstract class AbstractSingleBeanDefinitionParser extends AbstractBeanDefinitionParser {
/**
* Creates a {@link BeanDefinitionBuilder} instance for the
* {@link #getBeanClass bean Class} and passes it to the
* {@link #doParse} strategy method.
* @param element the element that is to be parsed into a single BeanDefinition
* @param parserContext the object encapsulating the current state of the parsing process
* @return the BeanDefinition resulting from the parsing of the supplied {@link Element}
* @throws IllegalStateException if the bean {@link Class} returned from
* {@link #getBeanClass(org.w3c.dom.Element)} is null
* @see #doParse
*/
protected final AbstractBeanDefinition parseInternal(Element element, ParserContext parserContext) {
Class beanClass = getBeanClass(element);
Assert.state(beanClass != null, "Class returned from getBeanClass(Element) must not be null");
BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(beanClass);
builder.setSource(parserContext.extractSource(element));
if (parserContext.isNested()) {
// Inner bean definition must receive same singleton status as containing bean.
builder.setSingleton(parserContext.getContainingBeanDefinition().isSingleton());
}
if (parserContext.isDefaultLazyInit()) {
// Default-lazy-init applies to custom bean definitions as well.
builder.setLazyInit(true);
}
doParse(element, parserContext, builder);
return builder.getBeanDefinition();
}
/**
* Determine the bean class corresponding to the supplied {@link Element}.
* @param element the Element that is being parsed
* @return the {@link Class} of the bean that is being defined via parsing the supplied Element
* (must not be null)
* @see #parseInternal(org.w3c.dom.Element, ParserContext)
*/
protected abstract Class getBeanClass(Element element);
/**
* Parse the supplied {@link Element} and populate the supplied
* {@link BeanDefinitionBuilder} as required.
*
The default implementation delegates to the doParse
* version without ParserContext argument.
* @param element the XML element being parsed
* @param parserContext the object encapsulating the current state of the parsing process
* @param builder used to define the BeanDefinition
* @see #doParse(Element, BeanDefinitionBuilder)
*/
protected void doParse(Element element, ParserContext parserContext, BeanDefinitionBuilder builder) {
doParse(element, builder);
}
/**
* Parse the supplied {@link Element} and populate the supplied
* {@link BeanDefinitionBuilder} as required.
*
The default implementation does nothing.
* @param element the XML element being parsed
* @param builder used to define the BeanDefinition
*/
protected void doParse(Element element, BeanDefinitionBuilder builder) {
}
}