| /* |
| * Copyright 2003-2004 The Apache Software Foundation |
| * |
| * Licensed 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.collections.bag; |
| |
| import java.util.Comparator; |
| |
| import org.apache.commons.collections.Predicate; |
| import org.apache.commons.collections.SortedBag; |
| |
| /** |
| * Decorates another <code>SortedBag</code> 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 IllegalArgumentException is thrown. |
| * <p> |
| * One usage would be to ensure that no null entries are added to the bag. |
| * <pre>SortedBag bag = PredicatedSortedBag.decorate(new TreeBag(), NotNullPredicate.INSTANCE);</pre> |
| * <p> |
| * This class is Serializable from Commons Collections 3.1. |
| * |
| * @since Commons Collections 3.0 |
| * @version $Revision: 1.1 $ $Date: 2009/05/27 22:16:34 $ |
| * |
| * @author Stephen Colebourne |
| * @author Paul Jack |
| */ |
| public class PredicatedSortedBag |
| extends PredicatedBag implements SortedBag { |
| |
| /** 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 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 IllegalArgumentException if bag or predicate is null |
| * @throws IllegalArgumentException if the bag contains invalid elements |
| */ |
| public static SortedBag decorate(SortedBag bag, Predicate 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 IllegalArgumentException if bag or predicate is null |
| * @throws IllegalArgumentException if the bag contains invalid elements |
| */ |
| protected PredicatedSortedBag(SortedBag bag, Predicate predicate) { |
| super(bag, predicate); |
| } |
| |
| /** |
| * Gets the decorated sorted bag. |
| * |
| * @return the decorated bag |
| */ |
| protected SortedBag getSortedBag() { |
| return (SortedBag) getCollection(); |
| } |
| |
| //----------------------------------------------------------------------- |
| public Object first() { |
| return getSortedBag().first(); |
| } |
| |
| public Object last() { |
| return getSortedBag().last(); |
| } |
| |
| public Comparator comparator() { |
| return getSortedBag().comparator(); |
| } |
| |
| } |