| /* |
| * 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.Closure; |
| import org.apache.commons.collections.Predicate; |
| |
| /** |
| * Closure implementation that executes a closure repeatedly until a condition is met, |
| * like a do-while or while loop. |
| * |
| * @since Commons Collections 3.0 |
| * @version $Revision: 1.1 $ $Date: 2009/05/27 22:16:32 $ |
| * |
| * @author Stephen Colebourne |
| */ |
| public class WhileClosure implements Closure, Serializable { |
| |
| /** Serial version UID */ |
| private static final long serialVersionUID = -3110538116913760108L; |
| |
| /** The test condition */ |
| private final Predicate iPredicate; |
| /** The closure to call */ |
| private final Closure iClosure; |
| /** The flag, true is a do loop, false is a while */ |
| private final boolean iDoLoop; |
| |
| /** |
| * Factory method that performs validation. |
| * |
| * @param predicate the predicate used to evaluate when the loop terminates, not null |
| * @param closure the closure the execute, not null |
| * @param doLoop true to act as a do-while loop, always executing the closure once |
| * @return the <code>while</code> closure |
| * @throws IllegalArgumentException if the predicate or closure is null |
| */ |
| public static Closure getInstance(Predicate predicate, Closure closure, boolean doLoop) { |
| if (predicate == null) { |
| throw new IllegalArgumentException("Predicate must not be null"); |
| } |
| if (closure == null) { |
| throw new IllegalArgumentException("Closure must not be null"); |
| } |
| return new WhileClosure(predicate, closure, doLoop); |
| } |
| |
| /** |
| * Constructor that performs no validation. |
| * Use <code>getInstance</code> if you want that. |
| * |
| * @param predicate the predicate used to evaluate when the loop terminates, not null |
| * @param closure the closure the execute, not null |
| * @param doLoop true to act as a do-while loop, always executing the closure once |
| */ |
| public WhileClosure(Predicate predicate, Closure closure, boolean doLoop) { |
| super(); |
| iPredicate = predicate; |
| iClosure = closure; |
| iDoLoop = doLoop; |
| } |
| |
| /** |
| * Executes the closure until the predicate is false. |
| * |
| * @param input the input object |
| */ |
| public void execute(Object input) { |
| if (iDoLoop) { |
| iClosure.execute(input); |
| } |
| while (iPredicate.evaluate(input)) { |
| iClosure.execute(input); |
| } |
| } |
| |
| /** |
| * Gets the predicate in use. |
| * |
| * @return the predicate |
| * @since Commons Collections 3.1 |
| */ |
| public Predicate getPredicate() { |
| return iPredicate; |
| } |
| |
| /** |
| * Gets the closure. |
| * |
| * @return the closure |
| * @since Commons Collections 3.1 |
| */ |
| public Closure getClosure() { |
| return iClosure; |
| } |
| |
| /** |
| * Is the loop a do-while loop. |
| * |
| * @return true is do-while, false if while |
| * @since Commons Collections 3.1 |
| */ |
| public boolean isDoLoop() { |
| return iDoLoop; |
| } |
| |
| } |