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Posted to dev@commons.apache.org by sc...@apache.org on 2003/05/09 20:01:09 UTC
cvs commit: jakarta-commons/collections/src/java/org/apache/commons/collections/decorators UnmodifiableBoundedCollection.java
scolebourne 2003/05/09 11:01:08
Added: collections/src/java/org/apache/commons/collections/decorators
UnmodifiableBoundedCollection.java
Log:
Add BoundedCollection collection decorator
Revision Changes Path
1.1 jakarta-commons/collections/src/java/org/apache/commons/collections/decorators/UnmodifiableBoundedCollection.java
Index: UnmodifiableBoundedCollection.java
===================================================================
/*
* $Header: /home/cvs/jakarta-commons/collections/src/java/org/apache/commons/collections/decorators/UnmodifiableBoundedCollection.java,v 1.1 2003/05/09 18:01:08 scolebourne Exp $
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 2003 The Apache Software Foundation. All rights
* reserved.
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* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
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*
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* any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "The Jakarta Project", "Commons", and "Apache Software
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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* ====================================================================
*
* This software consists of voluntary contributions made by many
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*/
package org.apache.commons.collections.decorators;
import java.util.Collection;
import org.apache.commons.collections.BoundedCollection;
/**
* <code>UnmodifiableBoundedCollection</code> decorates another <code>BoundedCollection</code>
* to ensure it can't be altered.
* <p>
* If a BoundedCollection is first wrapped in some other collection decorator,
* such as synchronized or predicated, the BoundedCollection nature is lost.
* The factory on this class will attempt to retrieve the bounded nature by
* examining the package scope variables.
*
* @since Commons Collections 3.0
* @version $Revision: 1.1 $ $Date: 2003/05/09 18:01:08 $
*
* @author Stephen Colebourne
*/
public class UnmodifiableBoundedCollection extends UnmodifiableCollection implements BoundedCollection {
/**
* Factory method to create an unmodifiable bounded collection.
*
* @param bag the bag to decorate, must not be null
* @throws IllegalArgumentException if bag is null
*/
public static BoundedCollection decorate(BoundedCollection coll) {
return new UnmodifiableBoundedCollection(coll);
}
/**
* Factory method to create an unmodifiable bounded collection.
* <p>
* This method is capable of drilling down through other decorators to find
* a suitable BoundedCollection
*
* @param bag the bag to decorate, must not be null
* @throws IllegalArgumentException if bag is null
*/
public static BoundedCollection decorateUsing(Collection coll) {
if (coll == null) {
throw new IllegalArgumentException("The collection must not be null");
}
// handle decorators
for (int i = 0; i < 1000; i++) { // counter to prevent infinite looping
if (coll instanceof BoundedCollection) {
break; // normal loop exit
} else if (coll instanceof AbstractCollectionDecorator) {
coll = ((AbstractCollectionDecorator) coll).collection;
} else if (coll instanceof SynchronizedCollection) {
coll = ((SynchronizedCollection) coll).collection;
} else {
break; // normal loop exit
}
}
if (coll instanceof BoundedCollection == false) {
throw new IllegalArgumentException("The collection is not a bounded collection");
}
return new UnmodifiableBoundedCollection((BoundedCollection) coll);
}
/**
* Constructor that wraps (not copies).
*
* @param coll the collection to decorate, must not be null
* @throws IllegalArgumentException if bag is null
*/
protected UnmodifiableBoundedCollection(BoundedCollection coll) {
super(coll);
}
//-----------------------------------------------------------------------
public boolean isFull() {
return ((BoundedCollection) collection).isFull();
}
public int maxSize() {
return ((BoundedCollection) collection).maxSize();
}
}
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