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 * 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
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 *      http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.commons.collections4.functors;

import org.apache.commons.collections4.Closure;
import org.apache.commons.collections4.Predicate;

Closure implementation that executes a closure repeatedly until a condition is met, like a do-while or while loop.

WARNING: from v4.1 onwards this class will not be serializable anymore in order to prevent potential remote code execution exploits. Please refer to COLLECTIONS-580 for more details.

Since:3.0
/** * Closure implementation that executes a closure repeatedly until a condition is met, * like a do-while or while loop. * <p> * <b>WARNING:</b> from v4.1 onwards this class will <b>not</b> be serializable anymore * in order to prevent potential remote code execution exploits. Please refer to * <a href="https://issues.apache.org/jira/browse/COLLECTIONS-580">COLLECTIONS-580</a> * for more details. * * @since 3.0 */
public class WhileClosure<E> implements Closure<E> {
The test condition
/** The test condition */
private final Predicate<? super E> iPredicate;
The closure to call
/** The closure to call */
private final Closure<? super E> iClosure;
The flag, true is a do loop, false is a while
/** The flag, true is a do loop, false is a while */
private final boolean iDoLoop;
Factory method that performs validation.
Params:
  • predicate – the predicate used to evaluate when the loop terminates, not null
  • closure – the closure the execute, not null
  • doLoop – true to act as a do-while loop, always executing the closure once
Type parameters:
  • <E> – the type that the closure acts on
Throws:
Returns:the while closure
/** * Factory method that performs validation. * * @param <E> the type that the closure acts on * @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 NullPointerException if the predicate or closure is null */
public static <E> Closure<E> whileClosure(final Predicate<? super E> predicate, final Closure<? super E> closure, final boolean doLoop) { if (predicate == null) { throw new NullPointerException("Predicate must not be null"); } if (closure == null) { throw new NullPointerException("Closure must not be null"); } return new WhileClosure<>(predicate, closure, doLoop); }
Constructor that performs no validation. Use whileClosure if you want that.
Params:
  • predicate – the predicate used to evaluate when the loop terminates, not null
  • closure – the closure the execute, not null
  • doLoop – true to act as a do-while loop, always executing the closure once
/** * Constructor that performs no validation. * Use <code>whileClosure</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(final Predicate<? super E> predicate, final Closure<? super E> closure, final boolean doLoop) { super(); iPredicate = predicate; iClosure = closure; iDoLoop = doLoop; }
Executes the closure until the predicate is false.
Params:
  • input – the input object
/** * Executes the closure until the predicate is false. * * @param input the input object */
@Override public void execute(final E input) { if (iDoLoop) { iClosure.execute(input); } while (iPredicate.evaluate(input)) { iClosure.execute(input); } }
Gets the predicate in use.
Returns:the predicate
Since:3.1
/** * Gets the predicate in use. * * @return the predicate * @since 3.1 */
public Predicate<? super E> getPredicate() { return iPredicate; }
Gets the closure.
Returns:the closure
Since:3.1
/** * Gets the closure. * * @return the closure * @since 3.1 */
public Closure<? super E> getClosure() { return iClosure; }
Is the loop a do-while loop.
Returns:true is do-while, false if while
Since:3.1
/** * Is the loop a do-while loop. * * @return true is do-while, false if while * @since 3.1 */
public boolean isDoLoop() { return iDoLoop; } }