/*
* 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.beans.factory.config;
import java.util.ArrayList;
import java.util.List;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.TypeConverter;
import org.springframework.core.GenericCollectionTypeResolver;
/**
* Simple factory for shared List instances. Allows for central setup
* of Lists via the "list" element in XML bean definitions.
*
* @author Juergen Hoeller
* @since 09.12.2003
* @see SetFactoryBean
* @see MapFactoryBean
*/
public class ListFactoryBean extends AbstractFactoryBean<List> {
private List sourceList;
private Class targetListClass;
/**
* Set the source List, typically populated via XML "list" elements.
*/
public void setSourceList(List sourceList) {
this.sourceList = sourceList;
}
/**
* Set the class to use for the target List. Can be populated with a fully
* qualified class name when defined in a Spring application context.
* <p>Default is a <code>java.util.ArrayList</code>.
* @see java.util.ArrayList
*/
public void setTargetListClass(Class targetListClass) {
if (targetListClass == null) {
throw new IllegalArgumentException("'targetListClass' must not be null");
}
if (!List.class.isAssignableFrom(targetListClass)) {
throw new IllegalArgumentException("'targetListClass' must implement [java.util.List]");
}
this.targetListClass = targetListClass;
}
@Override
public Class<List> getObjectType() {
return List.class;
}
@Override
@SuppressWarnings("unchecked")
protected List createInstance() {
if (this.sourceList == null) {
throw new IllegalArgumentException("'sourceList' is required");
}
List result = null;
if (this.targetListClass != null) {
result = (List) BeanUtils.instantiateClass(this.targetListClass);
}
else {
result = new ArrayList(this.sourceList.size());
}
Class valueType = null;
if (this.targetListClass != null) {
valueType = GenericCollectionTypeResolver.getCollectionType(this.targetListClass);
}
if (valueType != null) {
TypeConverter converter = getBeanTypeConverter();
for (Object elem : this.sourceList) {
result.add(converter.convertIfNecessary(elem, valueType));
}
}
else {
result.addAll(this.sourceList);
}
return result;
}
}
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