org.apache.commons.collections.buffer
Class PredicatedBuffer<E>

java.lang.Object
  org.apache.commons.collections.collection.AbstractCollectionDecorator<E>
      org.apache.commons.collections.collection.AbstractSerializableCollectionDecorator<E>
          org.apache.commons.collections.collection.PredicatedCollection<E>
              org.apache.commons.collections.buffer.PredicatedBuffer<E>

All Implemented Interfaces:

Serializable, Iterable<E>, Collection<E>, Buffer<E>

public class PredicatedBuffer<E>
extends PredicatedCollection<E>
implements Buffer<E>

Decorates another Buffer to validate that additions match a specified predicate.

This buffer exists to provide validation for the decorated buffer. It is normally created to decorate an empty buffer. If an object cannot be added to the buffer, an IllegalArgumentException is thrown.

One usage would be to ensure that no null entries are added to the buffer.

Buffer buffer = PredicatedBuffer.decorate(new UnboundedFifoBuffer(), NotNullPredicate.INSTANCE);

This class is Serializable from Commons Collections 3.1.

Since:

Commons Collections 3.0

Version:

$Revision: 1.1.1.1 $ $Date: 2005/05/23 04:33:53 $

Author:

Stephen Colebourne, Matt Hall, John Watkinson, Paul Jack

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.commons.collections.collection.PredicatedCollection

predicate

Fields inherited from class org.apache.commons.collections.collection.AbstractCollectionDecorator

collection

Constructor Summary

protected

PredicatedBuffer(Buffer<E> buffer, Predicate<? super E> predicate) Constructor that wraps (not copies).

Method Summary

static <E> Buffer<E>	decorate(Buffer<E> buffer, Predicate<? super E> predicate) Factory method to create a predicated (validating) buffer.
E	get() Gets the next object from the buffer without removing it.
protected Buffer<E>	getBuffer() Gets the buffer being decorated.
E	remove() Gets and removes the next object from the buffer.

Methods inherited from class org.apache.commons.collections.collection.PredicatedCollection

add, addAll, decorate, validate

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

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

add, addAll, clear, contains, containsAll, equals, hashCode, isEmpty, iterator, remove, removeAll, retainAll, size, toArray, toArray

Constructor Detail

PredicatedBuffer

protected PredicatedBuffer(Buffer<E> buffer,
                           Predicate<? super E> predicate)

Constructor that wraps (not copies).

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

Parameters:

buffer - the buffer to decorate, must not be null

predicate - the predicate to use for validation, must not be null

Throws:

IllegalArgumentException - if buffer or predicate is null

IllegalArgumentException - if the buffer contains invalid elements

Method Detail

decorate

public static <E> Buffer<E> decorate(Buffer<E> buffer,
                                     Predicate<? super E> predicate)

Factory method to create a predicated (validating) buffer.

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

Parameters:

buffer - the buffer to decorate, must not be null

predicate - the predicate to use for validation, must not be null

Returns:

a new predicated Buffer

Throws:

IllegalArgumentException - if buffer or predicate is null

IllegalArgumentException - if the buffer contains invalid elements

getBuffer

protected Buffer<E> getBuffer()

Gets the buffer being decorated.

Returns:

the decorated buffer

get

public E get()

Description copied from interface: Buffer

Gets the next object from the buffer without removing it.

Specified by:

get in interface Buffer<E>

Returns:

the next object in the buffer, which is not removed

remove

public E remove()

Description copied from interface: Buffer

Gets and removes the next object from the buffer.

Specified by:

remove in interface Buffer<E>

Returns:

the next object in the buffer, which is also removed