org.springframework.beans.factory.support.ManagedList Maven / Gradle / Ivy
/*
* Copyright 2002-2018 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
*
* https://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 java.util.ArrayList;
import java.util.List;
import org.springframework.beans.BeanMetadataElement;
import org.springframework.beans.Mergeable;
import org.springframework.lang.Nullable;
/**
* Tag collection class used to hold managed List elements, which may
* include runtime bean references (to be resolved into bean objects).
*
* @author Rod Johnson
* @author Rob Harrop
* @author Juergen Hoeller
* @since 27.05.2003
* @param the element type
*/
@SuppressWarnings("serial")
public class ManagedList extends ArrayList implements Mergeable, BeanMetadataElement {
@Nullable
private Object source;
@Nullable
private String elementTypeName;
private boolean mergeEnabled;
public ManagedList() {
}
public ManagedList(int initialCapacity) {
super(initialCapacity);
}
/**
* Set the configuration source {@code Object} for this metadata element.
* The exact type of the object will depend on the configuration mechanism used.
*/
public void setSource(@Nullable Object source) {
this.source = source;
}
@Override
@Nullable
public Object getSource() {
return this.source;
}
/**
* Set the default element type name (class name) to be used for this list.
*/
public void setElementTypeName(String elementTypeName) {
this.elementTypeName = elementTypeName;
}
/**
* Return the default element type name (class name) to be used for this list.
*/
@Nullable
public String getElementTypeName() {
return this.elementTypeName;
}
/**
* Set whether merging should be enabled for this collection,
* in case of a 'parent' collection value being present.
*/
public void setMergeEnabled(boolean mergeEnabled) {
this.mergeEnabled = mergeEnabled;
}
@Override
public boolean isMergeEnabled() {
return this.mergeEnabled;
}
@Override
@SuppressWarnings("unchecked")
public List merge(@Nullable Object parent) {
if (!this.mergeEnabled) {
throw new IllegalStateException("Not allowed to merge when the 'mergeEnabled' property is set to 'false'");
}
if (parent == null) {
return this;
}
if (!(parent instanceof List)) {
throw new IllegalArgumentException("Cannot merge with object of type [" + parent.getClass() + "]");
}
List merged = new ManagedList<>();
merged.addAll((List) parent);
merged.addAll(this);
return merged;
}
}