org.apache.commons.collections.set.PredicatedSortedSet Maven / Gradle / Ivy
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/*
* 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 SortedSet
to validate that all additions
* match a specified predicate.
*
* 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.
*
* One usage would be to ensure that no null entries are added to the set.
*
SortedSet set = PredicatedSortedSet.decorate(new TreeSet(), NotNullPredicate.INSTANCE);
*
* This class is Serializable from Commons Collections 3.1.
*
* @since Commons Collections 3.0
* @version $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (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.
*
* 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).
*
* 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();
}
}