| /* |
| * 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.functor.core.composite; |
| |
| import java.io.Serializable; |
| |
| import org.apache.commons.functor.Predicate; |
| |
| /** |
| * {@link #test Tests} to the logical inverse |
| * of some other predicate. |
| * <p> |
| * Note that although this class implements |
| * {@link Serializable}, a given instance will |
| * only be truly <code>Serializable</code> if the |
| * underlying functor is. Attempts to serialize |
| * an instance whose delegate is not |
| * <code>Serializable</code> will result in an exception. |
| * </p> |
| * @version $Revision$ $Date$ |
| * @author Rodney Waldhoff |
| */ |
| public final class Not implements Predicate, Serializable { |
| |
| /** |
| * serialVersionUID declaration. |
| */ |
| private static final long serialVersionUID = 8268713706856765874L; |
| // attributes |
| // ------------------------------------------------------------------------ |
| /** |
| * The adapted predicate has to be negated. |
| */ |
| private final Predicate predicate; |
| |
| // constructor |
| // ------------------------------------------------------------------------ |
| /** |
| * Create a new Not. |
| * @param predicate Predicate to negate |
| */ |
| public Not(Predicate predicate) { |
| if (predicate == null) { |
| throw new IllegalArgumentException("Predicate argument was null"); |
| } |
| this.predicate = predicate; |
| } |
| |
| // predicate interface |
| // ------------------------------------------------------------------------ |
| /** |
| * {@inheritDoc} |
| */ |
| public boolean test() { |
| return !(predicate.test()); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public boolean equals(Object that) { |
| return that == this || (that instanceof Not && equals((Not) that)); |
| } |
| |
| /** |
| * Learn whether another Not is equal to this. |
| * @param that the Not to test |
| * @return boolean |
| */ |
| public boolean equals(Not that) { |
| return null != that && (null == predicate ? null == that.predicate : predicate.equals(that.predicate)); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public int hashCode() { |
| int hash = "Not".hashCode(); |
| if (null != predicate) { |
| hash ^= predicate.hashCode(); |
| } |
| return hash; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public String toString() { |
| return "Not<" + predicate + ">"; |
| } |
| |
| // static |
| // ------------------------------------------------------------------------ |
| /** |
| * Get a Not instance for <code>that</code>. |
| * @param that Predicate to negate |
| * @return Not |
| */ |
| public static Predicate not(Predicate that) { |
| return null == that ? null : new Not(that); |
| } |
| } |