- /*
- * 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 false if the input is null.
- *
- * @since Commons Collections 3.0
- * @version $Revision: 1.6 $ $Date: 2004/05/31 16:43:17 $
- *
- * @author Stephen Colebourne
- */
- public final class NullIsFalsePredicate implements Predicate, PredicateDecorator, Serializable {
-
- /** Serial version UID */
- static final long serialVersionUID = -2997501534564735525L;
-
- /** The predicate to decorate */
- private final Predicate iPredicate;
-
- /**
- * Factory to create the null false predicate.
- *
- * @param predicate the predicate to decorate, not null
- * @return the predicate
- * @throws IllegalArgumentException if the predicate is null
- */
- public static Predicate getInstance(Predicate predicate) {
- if (predicate == null) {
- throw new IllegalArgumentException("Predicate must not be null");
- }
- return new NullIsFalsePredicate(predicate);
- }
-
- /**
- * Constructor that performs no validation.
- * Use <code>getInstance</code> if you want that.
- *
- * @param predicate the predicate to call after the null check
- */
- public NullIsFalsePredicate(Predicate predicate) {
- super();
- iPredicate = predicate;
- }
-
- /**
- * Evaluates the predicate returning the result of the decorated predicate
- * once a null check is performed.
- *
- * @param object the input object
- * @return true if decorated predicate returns true, false if input is null
- */
- public boolean evaluate(Object object) {
- if (object == null) {
- return false;
- }
- return iPredicate.evaluate(object);
- }
-
- /**
- * Gets the predicate being decorated.
- *
- * @return the predicate as the only element in an array
- * @since Commons Collections 3.1
- */
- public Predicate[] getPredicates() {
- return new Predicate[] {iPredicate};
- }
-
- }