/*
|
* CDDL HEADER START
|
*
|
* The contents of this file are subject to the terms of the
|
* Common Development and Distribution License, Version 1.0 only
|
* (the "License"). You may not use this file except in compliance
|
* with the License.
|
*
|
* You can obtain a copy of the license at
|
* trunk/opends/resource/legal-notices/OpenDS.LICENSE
|
* or https://OpenDS.dev.java.net/OpenDS.LICENSE.
|
* See the License for the specific language governing permissions
|
* and limitations under the License.
|
*
|
* When distributing Covered Code, include this CDDL HEADER in each
|
* file and include the License file at
|
* trunk/opends/resource/legal-notices/OpenDS.LICENSE. If applicable,
|
* add the following below this CDDL HEADER, with the fields enclosed
|
* by brackets "[]" replaced with your own identifying information:
|
* Portions Copyright [yyyy] [name of copyright owner]
|
*
|
* CDDL HEADER END
|
*
|
*
|
* Copyright 2009 Sun Microsystems, Inc.
|
*/
|
|
package com.sun.opends.sdk.util;
|
|
|
|
import java.util.AbstractCollection;
|
import java.util.Collection;
|
import java.util.Iterator;
|
|
|
|
/**
|
* Additional {@code Collection} based utility methods.
|
*/
|
public final class Collections2
|
{
|
private static final class TransformedCollection<M, N, P> extends
|
AbstractCollection<N> implements Collection<N>
|
{
|
|
private final Collection<M> collection;
|
|
private final Function<? super M, ? extends N, P> funcMtoN;
|
|
private final Function<? super N, ? extends M, P> funcNtoM;
|
|
private final P p;
|
|
|
|
private TransformedCollection(final Collection<M> collection,
|
final Function<? super M, ? extends N, P> funcMtoN,
|
final Function<? super N, ? extends M, P> funcNtoM, final P p)
|
{
|
this.collection = collection;
|
this.funcMtoN = funcMtoN;
|
this.funcNtoM = funcNtoM;
|
this.p = p;
|
}
|
|
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public boolean add(final N e)
|
{
|
return collection.add(funcNtoM.apply(e, p));
|
}
|
|
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public void clear()
|
{
|
collection.clear();
|
}
|
|
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
@SuppressWarnings("unchecked")
|
public boolean contains(final Object o)
|
{
|
final N tmp = (N) o;
|
return collection.contains(funcNtoM.apply(tmp, p));
|
}
|
|
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public boolean isEmpty()
|
{
|
return collection.isEmpty();
|
}
|
|
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public Iterator<N> iterator()
|
{
|
return Iterators.transform(collection.iterator(), funcMtoN, p);
|
}
|
|
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
@SuppressWarnings("unchecked")
|
public boolean remove(final Object o)
|
{
|
final N tmp = (N) o;
|
return collection.remove(funcNtoM.apply(tmp, p));
|
}
|
|
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public int size()
|
{
|
return collection.size();
|
}
|
|
}
|
|
|
|
/**
|
* Returns a view of {@code collection} whose values have been mapped to
|
* elements of type {@code N} using {@code funcMtoN}. The returned collection
|
* supports all operations.
|
*
|
* @param <M>
|
* The type of elements contained in {@code collection}.
|
* @param <N>
|
* The type of elements contained in the returned collection.
|
* @param <P>
|
* The type of the additional parameter to the function's {@code
|
* apply} method. Use {@link java.lang.Void} for functions that do
|
* not need an additional parameter.
|
* @param collection
|
* The collection to be transformed.
|
* @param funcMtoN
|
* A function which maps values of type {@code M} to values of type
|
* {@code N}. This function will be used when retrieving values from
|
* {@code collection}.
|
* @param funcNtoM
|
* A function which maps values of type {@code N} to values of type
|
* {@code M}. This function will be used when performing queries and
|
* adding values to {@code collection} .
|
* @param p
|
* A predicate specified parameter.
|
* @return A view of {@code collection} whose values have been mapped to
|
* elements of type {@code N} using {@code funcMtoN}.
|
*/
|
public static <M, N, P> Collection<N> transform(
|
final Collection<M> collection,
|
final Function<? super M, ? extends N, P> funcMtoN,
|
final Function<? super N, ? extends M, P> funcNtoM, final P p)
|
{
|
return new TransformedCollection<M, N, P>(collection, funcMtoN, funcNtoM, p);
|
}
|
|
|
|
/**
|
* Returns a view of {@code collection} whose values have been mapped to
|
* elements of type {@code N} using {@code funcMtoN}. The returned collection
|
* supports all operations.
|
*
|
* @param <M>
|
* The type of elements contained in {@code collection}.
|
* @param <N>
|
* The type of elements contained in the returned collection.
|
* @param collection
|
* The collection to be transformed.
|
* @param funcMtoN
|
* A function which maps values of type {@code M} to values of type
|
* {@code N}. This function will be used when retrieving values from
|
* {@code collection}.
|
* @param funcNtoM
|
* A function which maps values of type {@code N} to values of type
|
* {@code M}. This function will be used when performing queries and
|
* adding values to {@code collection} .
|
* @return A view of {@code collection} whose values have been mapped to
|
* elements of type {@code N} using {@code funcMtoN}.
|
*/
|
public static <M, N> Collection<N> transform(final Collection<M> collection,
|
final Function<? super M, ? extends N, Void> funcMtoN,
|
final Function<? super N, ? extends M, Void> funcNtoM)
|
{
|
return new TransformedCollection<M, N, Void>(collection, funcMtoN,
|
funcNtoM, null);
|
}
|
|
|
|
// Prevent instantiation
|
private Collections2()
|
{
|
// Do nothing.
|
}
|
|
}
|
