PredicatedSortedBag.java
- /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- package org.apache.commons.collections4.bag;
- import java.util.Comparator;
- import org.apache.commons.collections4.Predicate;
- import org.apache.commons.collections4.SortedBag;
- /**
- * Decorates another {@link SortedBag} to validate that additions
- * match a specified predicate.
- * <p>
- * This bag exists to provide validation for the decorated bag.
- * It is normally created to decorate an empty bag.
- * If an object cannot be added to the bag, an {@link IllegalArgumentException} is thrown.
- * </p>
- * <p>
- * One usage would be to ensure that no null entries are added to the bag.
- * <pre>
- * SortedBag bag = PredicatedSortedBag.predicatedSortedBag(new TreeBag(), NotNullPredicate.INSTANCE);
- * </pre>
- * <p>
- * This class is Serializable from Commons Collections 3.1.
- * </p>
- *
- * @param <E> the type of elements in this bag
- * @since 3.0
- */
- public class PredicatedSortedBag<E> extends PredicatedBag<E> implements SortedBag<E> {
- /** Serialization version */
- private static final long serialVersionUID = 3448581314086406616L;
- /**
- * Factory method to create a predicated (validating) bag.
- * <p>
- * If there are any elements already in the bag being decorated, they
- * are validated.
- *
- * @param <E> the type of the elements in the bag
- * @param bag the bag to decorate, must not be null
- * @param predicate the predicate to use for validation, must not be null
- * @return a new predicated SortedBag
- * @throws NullPointerException if bag or predicate is null
- * @throws IllegalArgumentException if the bag contains invalid elements
- * @since 4.0
- */
- public static <E> PredicatedSortedBag<E> predicatedSortedBag(final SortedBag<E> bag,
- final Predicate<? super E> predicate) {
- return new PredicatedSortedBag<>(bag, predicate);
- }
- /**
- * Constructor that wraps (not copies).
- * <p>If there are any elements already in the bag being decorated, they
- * are validated.
- *
- * @param bag the bag to decorate, must not be null
- * @param predicate the predicate to use for validation, must not be null
- * @throws NullPointerException if bag or predicate is null
- * @throws IllegalArgumentException if the bag contains invalid elements
- */
- protected PredicatedSortedBag(final SortedBag<E> bag, final Predicate<? super E> predicate) {
- super(bag, predicate);
- }
- @Override
- public Comparator<? super E> comparator() {
- return decorated().comparator();
- }
- /**
- * Gets the decorated sorted bag.
- *
- * @return the decorated bag
- */
- @Override
- protected SortedBag<E> decorated() {
- return (SortedBag<E>) super.decorated();
- }
- @Override
- public E first() {
- return decorated().first();
- }
- @Override
- public E last() {
- return decorated().last();
- }
- }