org.apache.commons.collections.collection
Class PredicatedCollection
- Collection, Serializable
public class PredicatedCollection
Decorates another
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.
$Revision: 1.7 $ $Date: 2004/06/03 22:02:13 $- Stephen Colebourne
- Paul Jack
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.
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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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add , addAll , clear , contains , containsAll , equals , getCollection , hashCode , isEmpty , iterator , remove , removeAll , retainAll , size , toArray , toArray , toString |
predicate
protected final Predicate predicate
The predicate to use
PredicatedCollection
protected PredicatedCollection(Collection coll,
Predicate predicate)
Constructor that wraps (not copies).
If there are any elements already in the collection being decorated, they
are validated.
coll
- the collection to decorate, must not be nullpredicate
- the predicate to use for validation, must not be null
add
public boolean add(Object object)
Override to validate the object being added to ensure it matches
the predicate.
- add in interface AbstractCollectionDecorator
object
- the object being added
- the result of adding to the underlying collection
addAll
public boolean addAll(Collection coll)
Override to validate the objects being added to ensure they match
the predicate. If any one fails, no update is made to the underlying
collection.
- addAll in interface AbstractCollectionDecorator
coll
- the collection being added
- the result of adding to the underlying collection
decorate
public static Collection decorate(Collection coll,
Predicate predicate)
Factory method to create a predicated (validating) collection.
If there are any elements already in the collection being decorated, they
are validated.
coll
- the collection to decorate, must not be nullpredicate
- the predicate to use for validation, must not be null
- a new predicated collection
validate
protected void validate(Object object)
Validates the object being added to ensure it matches the predicate.
The predicate itself should not throw an exception, but return false to
indicate that the object cannot be added.
object
- the object being added
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