Commons Collections example source code file (PredicatedSortedSet.java)

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Java - Commons Collections tags/keywords

comparator, object, object, predicate, predicate, predicatedset, predicatedsortedset, predicatedsortedset, sortedset, sortedset, util

The Commons Collections PredicatedSortedSet.java source code

/*
 *  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.collections.set;

import java.util.Comparator;
import java.util.SortedSet;

import org.apache.commons.collections.Predicate;

/**
 * Decorates another <code>SortedSet to validate that all additions
 * match a specified predicate.
 * <p>
 * This set exists to provide validation for the decorated set.
 * It is normally created to decorate an empty set.
 * If an object cannot be added to the set, an IllegalArgumentException is thrown.
 * <p>
 * One usage would be to ensure that no null entries are added to the set.
 * <pre>SortedSet set = PredicatedSortedSet.decorate(new TreeSet(), NotNullPredicate.INSTANCE);

* <p> * This class is Serializable from Commons Collections 3.1. * * @since Commons Collections 3.0 * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $ * * @author Stephen Colebourne * @author Paul Jack */ public class PredicatedSortedSet extends PredicatedSet implements SortedSet { /** Serialization version */ private static final long serialVersionUID = -9110948148132275052L; /** * Factory method to create a predicated (validating) sorted set. * <p> * If there are any elements already in the set being decorated, they * are validated. * * @param set the set to decorate, must not be null * @param predicate the predicate to use for validation, must not be null * @throws IllegalArgumentException if set or predicate is null * @throws IllegalArgumentException if the set contains invalid elements */ public static SortedSet decorate(SortedSet set, Predicate predicate) { return new PredicatedSortedSet(set, predicate); } //----------------------------------------------------------------------- /** * Constructor that wraps (not copies). * <p> * If there are any elements already in the set being decorated, they * are validated. * * @param set the set to decorate, must not be null * @param predicate the predicate to use for validation, must not be null * @throws IllegalArgumentException if set or predicate is null * @throws IllegalArgumentException if the set contains invalid elements */ protected PredicatedSortedSet(SortedSet set, Predicate predicate) { super(set, predicate); } /** * Gets the sorted set being decorated. * * @return the decorated sorted set */ private SortedSet getSortedSet() { return (SortedSet) getCollection(); } //----------------------------------------------------------------------- public SortedSet subSet(Object fromElement, Object toElement) { SortedSet sub = getSortedSet().subSet(fromElement, toElement); return new PredicatedSortedSet(sub, predicate); } public SortedSet headSet(Object toElement) { SortedSet sub = getSortedSet().headSet(toElement); return new PredicatedSortedSet(sub, predicate); } public SortedSet tailSet(Object fromElement) { SortedSet sub = getSortedSet().tailSet(fromElement); return new PredicatedSortedSet(sub, predicate); } public Object first() { return getSortedSet().first(); } public Object last() { return getSortedSet().last(); } public Comparator comparator() { return getSortedSet().comparator(); } }