/*
* 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;
/**
* Interface representing an object whose value set can be merged with
* that of a parent object.
*
* @author Rob Harrop
* @since 2.0
* @see org.springframework.beans.factory.support.ManagedSet
* @see org.springframework.beans.factory.support.ManagedList
* @see org.springframework.beans.factory.support.ManagedMap
* @see org.springframework.beans.factory.support.ManagedProperties
*/
public interface Mergeable {
/**
* Is merging enabled for this particular instance?
*/
boolean isMergeEnabled();
/**
* Merge the current value set with that of the supplied object.
* <p>The supplied object is considered the parent, and values in
* the callee's value set must override those of the supplied object.
* @param parent the object to merge with
* @return the result of the merge operation
* @throws IllegalArgumentException if the supplied parent is <code>null</code>
* @exception IllegalStateException if merging is not enabled for this instance
* (i.e. <code>mergeEnabled</code> equals <code>false</code>).
*/
Object merge(Object parent);
}
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