org.apache.commons.collections.bag
Class TypedBag

java.lang.Object
  org.apache.commons.collections.bag.TypedBag

public class TypedBag
extends java.lang.Object

Decorates another Bag to validate that elements added are of a specific type.

The validation of additions is performed via an instanceof test against a specified Class. If an object cannot be added to the collection, an IllegalArgumentException is thrown.

Since:

Commons Collections 3.0

Version:

$Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $

Author:

Stephen Colebourne, Matthew Hawthorne

Constructor Summary

protected

TypedBag() Restrictive constructor.

Method Summary

static Bag

decorate(Bag bag, java.lang.Class type) Factory method to create a typed bag.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TypedBag

protected TypedBag()

Restrictive constructor.

Method Detail

decorate

public static Bag decorate(Bag bag,
                           java.lang.Class type)

Factory method to create a typed bag.

If there are any elements already in the bag being decorated, they are validated.

Parameters:

bag - the bag to decorate, must not be null

type - the type to allow into the bag, must not be null

Returns:

a new typed Bag

Throws:

java.lang.IllegalArgumentException - if bag or type is null

java.lang.IllegalArgumentException - if the bag contains invalid elements