/*
|
* 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 legal-notices/CDDLv1_0.txt
|
* or http://forgerock.org/license/CDDLv1.0.html.
|
* 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 legal-notices/CDDLv1_0.txt.
|
* 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 2009-2010 Sun Microsystems, Inc.
|
*/
|
|
package com.forgerock.opendj.util;
|
|
import java.util.AbstractCollection;
|
import java.util.Collection;
|
import java.util.Iterator;
|
import java.util.List;
|
import java.util.ListIterator;
|
|
import org.forgerock.opendj.ldap.Function;
|
|
/**
|
* Additional {@code Collection} based utility methods.
|
*/
|
public final class Collections2 {
|
private static class TransformedCollection<M, N, P, C extends Collection<M>> extends
|
AbstractCollection<N> implements Collection<N> {
|
|
protected final C collection;
|
|
protected final Function<? super M, ? extends N, P> funcMtoN;
|
|
protected final Function<? super N, ? extends M, P> funcNtoM;
|
|
protected final P p;
|
|
protected TransformedCollection(final C 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.transformedIterator(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();
|
}
|
|
}
|
|
private static final class TransformedList<M, N, P> extends
|
TransformedCollection<M, N, P, List<M>> implements List<N> {
|
|
private TransformedList(final List<M> list,
|
final Function<? super M, ? extends N, P> funcMtoN,
|
final Function<? super N, ? extends M, P> funcNtoM, final P p) {
|
super(list, funcMtoN, funcNtoM, p);
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public void add(final int index, final N element) {
|
collection.add(index, funcNtoM.apply(element, p));
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public boolean addAll(final int index, final Collection<? extends N> c) {
|
// We cannot transform c here due to type-safety.
|
boolean result = false;
|
for (final N e : c) {
|
result |= add(e);
|
}
|
return result;
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public N get(final int index) {
|
return funcMtoN.apply(collection.get(index), p);
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
@SuppressWarnings("unchecked")
|
public int indexOf(final Object o) {
|
final N tmp = (N) o;
|
return collection.indexOf(funcNtoM.apply(tmp, p));
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
@SuppressWarnings("unchecked")
|
public int lastIndexOf(final Object o) {
|
final N tmp = (N) o;
|
return collection.lastIndexOf(funcNtoM.apply(tmp, p));
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public ListIterator<N> listIterator() {
|
return listIterator(0);
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public ListIterator<N> listIterator(final int index) {
|
final ListIterator<M> iterator = collection.listIterator(index);
|
return new ListIterator<N>() {
|
|
@Override
|
public void add(final N e) {
|
iterator.add(funcNtoM.apply(e, p));
|
}
|
|
@Override
|
public boolean hasNext() {
|
return iterator.hasNext();
|
}
|
|
@Override
|
public boolean hasPrevious() {
|
return iterator.hasPrevious();
|
}
|
|
@Override
|
public N next() {
|
return funcMtoN.apply(iterator.next(), p);
|
}
|
|
@Override
|
public int nextIndex() {
|
return iterator.nextIndex();
|
}
|
|
@Override
|
public N previous() {
|
return funcMtoN.apply(iterator.previous(), p);
|
}
|
|
@Override
|
public int previousIndex() {
|
return iterator.previousIndex();
|
}
|
|
@Override
|
public void remove() {
|
iterator.remove();
|
}
|
|
@Override
|
public void set(final N e) {
|
iterator.set(funcNtoM.apply(e, p));
|
}
|
|
};
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public N remove(final int index) {
|
return funcMtoN.apply(collection.remove(index), p);
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public N set(final int index, final N element) {
|
final M result = collection.set(index, funcNtoM.apply(element, p));
|
return funcMtoN.apply(result, p);
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
@Override
|
public List<N> subList(final int fromIndex, final int toIndex) {
|
final List<M> subList = collection.subList(fromIndex, toIndex);
|
return new TransformedList<M, N, P>(subList, 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 <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> transformedCollection(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<M>>(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> transformedCollection(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<M>>(collection, funcMtoN, funcNtoM,
|
null);
|
}
|
|
/**
|
* Returns a view of {@code list} whose values have been mapped to elements
|
* of type {@code N} using {@code funcMtoN}. The returned list supports all
|
* operations.
|
*
|
* @param <M>
|
* The type of elements contained in {@code list}.
|
* @param <N>
|
* The type of elements contained in the returned list.
|
* @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 list
|
* The list 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 list}.
|
* @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 list} .
|
* @param p
|
* A predicate specified parameter.
|
* @return A view of {@code list} whose values have been mapped to elements
|
* of type {@code N} using {@code funcMtoN}.
|
*/
|
public static <M, N, P> List<N> transformedList(final List<M> list,
|
final Function<? super M, ? extends N, P> funcMtoN,
|
final Function<? super N, ? extends M, P> funcNtoM, final P p) {
|
return new TransformedList<M, N, P>(list, funcMtoN, funcNtoM, p);
|
}
|
|
/**
|
* Returns a view of {@code list} whose values have been mapped to elements
|
* of type {@code N} using {@code funcMtoN}. The returned list supports all
|
* operations.
|
*
|
* @param <M>
|
* The type of elements contained in {@code list}.
|
* @param <N>
|
* The type of elements contained in the returned list.
|
* @param list
|
* The list 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 list}.
|
* @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 list} .
|
* @return A view of {@code list} whose values have been mapped to elements
|
* of type {@code N} using {@code funcMtoN}.
|
*/
|
public static <M, N> List<N> transformedList(final List<M> list,
|
final Function<? super M, ? extends N, Void> funcMtoN,
|
final Function<? super N, ? extends M, Void> funcNtoM) {
|
return new TransformedList<M, N, Void>(list, funcMtoN, funcNtoM, null);
|
}
|
|
// Prevent instantiation
|
private Collections2() {
|
// Do nothing.
|
}
|
|
}
|
