org.apache.commons.collections.collection
public class PredicatedCollection extends AbstractSerializableCollectionDecorator
Collection
to validate that additions
match a specified predicate.
This collection exists to provide validation for the decorated collection. It is normally created to decorate an empty collection. If an object cannot be added to the collection, an IllegalArgumentException is thrown.
One usage would be to ensure that no null entries are added to the collection.
Collection coll = PredicatedCollection.decorate(new ArrayList(), NotNullPredicate.INSTANCE);
This class is Serializable from Commons Collections 3.1.
Since: Commons Collections 3.0
Version: $Revision: 155406 $ $Date: 2005-02-26 12:55:26 +0000 (Sat, 26 Feb 2005) $
Field Summary | |
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protected Predicate | predicate The predicate to use |
Constructor Summary | |
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protected | PredicatedCollection(Collection coll, Predicate predicate)
Constructor that wraps (not copies).
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Method Summary | |
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boolean | add(Object object)
Override to validate the object being added to ensure it matches
the predicate.
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boolean | addAll(Collection coll)
Override to validate the objects being added to ensure they match
the predicate. |
static Collection | decorate(Collection coll, Predicate predicate)
Factory method to create a predicated (validating) collection.
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protected void | validate(Object object)
Validates the object being added to ensure it matches the predicate.
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If there are any elements already in the collection being decorated, they are validated.
Parameters: coll the collection to decorate, must not be null predicate the predicate to use for validation, must not be null
Throws: IllegalArgumentException if collection or predicate is null IllegalArgumentException if the collection contains invalid elements
Parameters: object the object being added
Returns: the result of adding to the underlying collection
Throws: IllegalArgumentException if the add is invalid
Parameters: coll the collection being added
Returns: the result of adding to the underlying collection
Throws: IllegalArgumentException if the add is invalid
If there are any elements already in the collection being decorated, they are validated.
Parameters: coll the collection to decorate, must not be null predicate the predicate to use for validation, must not be null
Returns: a new predicated collection
Throws: IllegalArgumentException if collection or predicate is null IllegalArgumentException if the collection contains invalid elements
The predicate itself should not throw an exception, but return false to indicate that the object cannot be added.
Parameters: object the object being added
Throws: IllegalArgumentException if the add is invalid