Class PredicatedCollection
- java.lang.Object
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- org.apache.commons.collections.collection.AbstractCollectionDecorator
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- org.apache.commons.collections.collection.AbstractSerializableCollectionDecorator
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- org.apache.commons.collections.collection.PredicatedCollection
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- All Implemented Interfaces:
java.io.Serializable
,java.lang.Iterable
,java.util.Collection
- Direct Known Subclasses:
PredicatedBag
,PredicatedBuffer
,PredicatedList
,PredicatedSet
public class PredicatedCollection extends AbstractSerializableCollectionDecorator
Decorates anotherCollection
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: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
- See Also:
- Serialized Form
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Field Summary
Fields Modifier and Type Field Description protected Predicate
predicate
The predicate to useprivate static long
serialVersionUID
Serialization version-
Fields inherited from class org.apache.commons.collections.collection.AbstractCollectionDecorator
collection
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Constructor Summary
Constructors Modifier Constructor Description protected
PredicatedCollection(java.util.Collection coll, Predicate predicate)
Constructor that wraps (not copies).
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
add(java.lang.Object object)
Override to validate the object being added to ensure it matches the predicate.boolean
addAll(java.util.Collection coll)
Override to validate the objects being added to ensure they match the predicate.static java.util.Collection
decorate(java.util.Collection coll, Predicate predicate)
Factory method to create a predicated (validating) collection.protected void
validate(java.lang.Object object)
Validates the object being added to ensure it matches the predicate.-
Methods inherited from class org.apache.commons.collections.collection.AbstractCollectionDecorator
clear, contains, containsAll, equals, getCollection, hashCode, isEmpty, iterator, remove, removeAll, retainAll, size, toArray, toArray, toString
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Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
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Field Detail
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serialVersionUID
private static final long serialVersionUID
Serialization version- See Also:
- Constant Field Values
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predicate
protected final Predicate predicate
The predicate to use
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Constructor Detail
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PredicatedCollection
protected PredicatedCollection(java.util.Collection coll, Predicate predicate)
Constructor that wraps (not copies).If there are any elements already in the collection being decorated, they are validated.
- Parameters:
coll
- the collection to decorate, must not be nullpredicate
- the predicate to use for validation, must not be null- Throws:
java.lang.IllegalArgumentException
- if collection or predicate is nulljava.lang.IllegalArgumentException
- if the collection contains invalid elements
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Method Detail
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decorate
public static java.util.Collection decorate(java.util.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.
- Parameters:
coll
- the collection to decorate, must not be nullpredicate
- the predicate to use for validation, must not be null- Returns:
- a new predicated collection
- Throws:
java.lang.IllegalArgumentException
- if collection or predicate is nulljava.lang.IllegalArgumentException
- if the collection contains invalid elements
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validate
protected void validate(java.lang.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.
- Parameters:
object
- the object being added- Throws:
java.lang.IllegalArgumentException
- if the add is invalid
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add
public boolean add(java.lang.Object object)
Override to validate the object being added to ensure it matches the predicate.- Specified by:
add
in interfacejava.util.Collection
- Overrides:
add
in classAbstractCollectionDecorator
- Parameters:
object
- the object being added- Returns:
- the result of adding to the underlying collection
- Throws:
java.lang.IllegalArgumentException
- if the add is invalid
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addAll
public boolean addAll(java.util.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.- Specified by:
addAll
in interfacejava.util.Collection
- Overrides:
addAll
in classAbstractCollectionDecorator
- Parameters:
coll
- the collection being added- Returns:
- the result of adding to the underlying collection
- Throws:
java.lang.IllegalArgumentException
- if the add is invalid
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