childbeandefinition.java

spring的源代码

/*
 * Copyright 2002-2006 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.support;

import org.springframework.beans.MutablePropertyValues;
import org.springframework.beans.factory.config.ConstructorArgumentValues;

/**
 * Bean definition for beans who inherit settings from their parent.
 *
 * <p>Will use the bean class of the parent if none specified, but can
 * also override it. In the latter case, the child bean class must be
 * compatible with the parent, i.e. accept the parent's property values
 * and constructor argument values, if any.
 *
 * <p>A child bean definition will inherit constructor argument values,
 * property values and method overrides from the parent, with the option
 * to add new values. If init method, destroy method and/or static factory
 * method are specified, they will override the corresponding parent settings.
 *
 * <p>The remaining settings will <i>always</i> be taken from the child definition:
 * depends on, autowire mode, dependency check, singleton, lazy init.
 *
 * @author Rod Johnson
 * @author Juergen Hoeller
 * @see RootBeanDefinition
 */
public class ChildBeanDefinition extends AbstractBeanDefinition {

	private final String parentName;


	/**
	 * Create a new ChildBeanDefinition for the given parent, to be
	 * configured through its bean properties and configuration methods.
	 * @param parentName the name of the parent bean
	 * @see #setBeanClass
	 * @see #setBeanClassName
	 * @see #setSingleton
	 * @see #setAutowireMode
	 * @see #setDependencyCheck
	 * @see #setConstructorArgumentValues
	 * @see #setPropertyValues
	 */
	public ChildBeanDefinition(String parentName) {
		super();
		this.parentName = parentName;
	}

	/**
	 * Create a new ChildBeanDefinition for the given parent.
	 * @param parentName the name of the parent bean
	 * @param pvs the additional property values of the child
	 */
	public ChildBeanDefinition(String parentName, MutablePropertyValues pvs) {
		super(null, pvs);
		this.parentName = parentName;
	}

	/**
	 * Create a new ChildBeanDefinition for the given parent.
	 * @param parentName the name of the parent bean
	 * @param cargs the constructor argument values to apply
	 * @param pvs the additional property values of the child
	 */
	public ChildBeanDefinition(
			String parentName, ConstructorArgumentValues cargs, MutablePropertyValues pvs) {

		super(cargs, pvs);
		this.parentName = parentName;
	}

	/**
	 * Create a new ChildBeanDefinition for the given parent,
	 * providing constructor arguments and property values.
	 * @param parentName the name of the parent bean
	 * @param beanClass the class of the bean to instantiate
	 * @param cargs the constructor argument values to apply
	 * @param pvs the property values to apply
	 */
	public ChildBeanDefinition(
			String parentName, Class beanClass, ConstructorArgumentValues cargs, MutablePropertyValues pvs) {

		super(cargs, pvs);
		this.parentName = parentName;
		setBeanClass(beanClass);
	}

	/**
	 * Create a new ChildBeanDefinition for the given parent,
	 * providing constructor arguments and property values.
	 * Takes a bean class name to avoid eager loading of the bean class.
	 * @param parentName the name of the parent bean
	 * @param beanClassName the name of the class to instantiate
	 * @param cargs the constructor argument values to apply
	 * @param pvs the property values to apply
	 */
	public ChildBeanDefinition(
			String parentName, String beanClassName, ConstructorArgumentValues cargs, MutablePropertyValues pvs) {

		super(cargs, pvs);
		this.parentName = parentName;
		setBeanClassName(beanClassName);
	}

	/**
	 * Return the name of the parent definition of this bean definition.
	 */
	public String getParentName() {
		return parentName;
	}


	public void validate() throws BeanDefinitionValidationException {
		super.validate();
		if (this.parentName == null) {
			throw new BeanDefinitionValidationException("parentName must be set in ChildBeanDefinition");
		}
	}

	public String toString() {
		StringBuffer sb = new StringBuffer("Child bean with parent '");
		sb.append(this.parentName).append("': ").append(super.toString());
		return sb.toString();
	}

}