- /*
- * 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: 1.5 $ $Date: 2004/05/16 11:47:38 $
- *
- * @author Stephen Colebourne
- */
- public class WhileClosure implements Closure, Serializable {
-
- /** Serial version UID */
- 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;
- }
-
- }