org.apache.commons.collections.collection.AbstractCollectionDecorator Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.commons.collections.collection;
import java.util.Collection;
import java.util.Iterator;
/**
* Decorates another Collection
to provide additional behaviour.
*
* Each method call made on this Collection
is forwarded to the
* decorated Collection
. This class is used as a framework on which
* to build to extensions such as synchronized and unmodifiable behaviour. The
* main advantage of decoration is that one decorator can wrap any implementation
* of Collection
, whereas sub-classing requires a new class to be
* written for each implementation.
*
* This implementation does not perform any special processing with
* {@link #iterator()}. Instead it simply returns the value from the
* wrapped collection. This may be undesirable, for example if you are trying
* to write an unmodifiable implementation it might provide a loophole.
*
* @since Commons Collections 3.0
* @version $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
*
* @author Stephen Colebourne
* @author Paul Jack
*/
public abstract class AbstractCollectionDecorator implements Collection {
/** The collection being decorated */
protected Collection collection;
/**
* Constructor only used in deserialization, do not use otherwise.
* @since Commons Collections 3.1
*/
protected AbstractCollectionDecorator() {
super();
}
/**
* Constructor that wraps (not copies).
*
* @param coll the collection to decorate, must not be null
* @throws IllegalArgumentException if the collection is null
*/
protected AbstractCollectionDecorator(Collection coll) {
if (coll == null) {
throw new IllegalArgumentException("Collection must not be null");
}
this.collection = coll;
}
/**
* Gets the collection being decorated.
*
* @return the decorated collection
*/
protected Collection getCollection() {
return collection;
}
//-----------------------------------------------------------------------
public boolean add(Object object) {
return collection.add(object);
}
public boolean addAll(Collection coll) {
return collection.addAll(coll);
}
public void clear() {
collection.clear();
}
public boolean contains(Object object) {
return collection.contains(object);
}
public boolean isEmpty() {
return collection.isEmpty();
}
public Iterator iterator() {
return collection.iterator();
}
public boolean remove(Object object) {
return collection.remove(object);
}
public int size() {
return collection.size();
}
public Object[] toArray() {
return collection.toArray();
}
public Object[] toArray(Object[] object) {
return collection.toArray(object);
}
public boolean containsAll(Collection coll) {
return collection.containsAll(coll);
}
public boolean removeAll(Collection coll) {
return collection.removeAll(coll);
}
public boolean retainAll(Collection coll) {
return collection.retainAll(coll);
}
public boolean equals(Object object) {
if (object == this) {
return true;
}
return collection.equals(object);
}
public int hashCode() {
return collection.hashCode();
}
public String toString() {
return collection.toString();
}
}