Java tutorial
/* * Copyright 2001-2004 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.functors; import java.io.Serializable; import org.apache.commons.collections.Predicate; /** * Predicate implementation that returns true if the input is the same object * as the one stored in this predicate by equals. * * @since Commons Collections 3.0 * @version $Revision: 1.5 $ $Date: 2004/05/16 11:16:01 $ * * @author Stephen Colebourne */ public final class EqualPredicate implements Predicate, Serializable { /** Serial version UID */ static final long serialVersionUID = 5633766978029907089L; /** The value to compare to */ private final Object iValue; /** * Factory to create the identity predicate. * * @param object the object to compare to * @return the predicate * @throws IllegalArgumentException if the predicate is null */ public static Predicate getInstance(Object object) { if (object == null) { return NullPredicate.INSTANCE; } return new EqualPredicate(object); } /** * Constructor that performs no validation. * Use <code>getInstance</code> if you want that. * * @param object the object to compare to */ public EqualPredicate(Object object) { super(); iValue = object; } /** * Evaluates the predicate returning true if the input equals the stored value. * * @param object the input object * @return true if input object equals stored value */ public boolean evaluate(Object object) { return (iValue.equals(object)); } /** * Gets the value. * * @return the value * @since Commons Collections 3.1 */ public Object getValue() { return iValue; } }