/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* 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
* 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 acts as an if statement calling one or other closure
based on a predicate.
Author: Stephen Colebourne, Matt Benson Since: Commons Collections 3.0 Version: $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
/**
* Closure implementation acts as an if statement calling one or other closure
* based on a predicate.
*
* @since Commons Collections 3.0
* @version $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
*
* @author Stephen Colebourne
* @author Matt Benson
*/
public class IfClosure implements Closure, Serializable {
Serial version UID /** Serial version UID */
private static final long serialVersionUID = 3518477308466486130L;
The test /** The test */
private final Predicate iPredicate;
The closure to use if true /** The closure to use if true */
private final Closure iTrueClosure;
The closure to use if false /** The closure to use if false */
private final Closure iFalseClosure;
Factory method that performs validation.
This factory creates a closure that performs no action when
the predicate is false.
Params: - predicate – predicate to switch on
- trueClosure – closure used if true
Throws: - IllegalArgumentException – if either argument is null
Returns: the if
closure Since: Commons Collections 3.2
/**
* Factory method that performs validation.
* <p>
* This factory creates a closure that performs no action when
* the predicate is false.
*
* @param predicate predicate to switch on
* @param trueClosure closure used if true
* @return the <code>if</code> closure
* @throws IllegalArgumentException if either argument is null
* @since Commons Collections 3.2
*/
public static Closure getInstance(Predicate predicate, Closure trueClosure) {
return getInstance(predicate, trueClosure, NOPClosure.INSTANCE);
}
Factory method that performs validation.
Params: - predicate – predicate to switch on
- trueClosure – closure used if true
- falseClosure – closure used if false
Throws: - IllegalArgumentException – if any argument is null
Returns: the if
closure
/**
* Factory method that performs validation.
*
* @param predicate predicate to switch on
* @param trueClosure closure used if true
* @param falseClosure closure used if false
* @return the <code>if</code> closure
* @throws IllegalArgumentException if any argument is null
*/
public static Closure getInstance(Predicate predicate, Closure trueClosure, Closure falseClosure) {
if (predicate == null) {
throw new IllegalArgumentException("Predicate must not be null");
}
if (trueClosure == null || falseClosure == null) {
throw new IllegalArgumentException("Closures must not be null");
}
return new IfClosure(predicate, trueClosure, falseClosure);
}
Constructor that performs no validation.
Use getInstance
if you want that.
This constructor creates a closure that performs no action when
the predicate is false.
Params: - predicate – predicate to switch on, not null
- trueClosure – closure used if true, not null
Since: Commons Collections 3.2
/**
* Constructor that performs no validation.
* Use <code>getInstance</code> if you want that.
* <p>
* This constructor creates a closure that performs no action when
* the predicate is false.
*
* @param predicate predicate to switch on, not null
* @param trueClosure closure used if true, not null
* @since Commons Collections 3.2
*/
public IfClosure(Predicate predicate, Closure trueClosure) {
this(predicate, trueClosure, NOPClosure.INSTANCE);
}
Constructor that performs no validation.
Use getInstance
if you want that.
Params: - predicate – predicate to switch on, not null
- trueClosure – closure used if true, not null
- falseClosure – closure used if false, not null
/**
* Constructor that performs no validation.
* Use <code>getInstance</code> if you want that.
*
* @param predicate predicate to switch on, not null
* @param trueClosure closure used if true, not null
* @param falseClosure closure used if false, not null
*/
public IfClosure(Predicate predicate, Closure trueClosure, Closure falseClosure) {
super();
iPredicate = predicate;
iTrueClosure = trueClosure;
iFalseClosure = falseClosure;
}
Executes the true or false closure accoring to the result of the predicate.
Params: - input – the input object
/**
* Executes the true or false closure accoring to the result of the predicate.
*
* @param input the input object
*/
public void execute(Object input) {
if (iPredicate.evaluate(input) == true) {
iTrueClosure.execute(input);
} else {
iFalseClosure.execute(input);
}
}
Gets the predicate.
Returns: the predicate Since: Commons Collections 3.1
/**
* Gets the predicate.
*
* @return the predicate
* @since Commons Collections 3.1
*/
public Predicate getPredicate() {
return iPredicate;
}
Gets the closure called when true.
Returns: the closure Since: Commons Collections 3.1
/**
* Gets the closure called when true.
*
* @return the closure
* @since Commons Collections 3.1
*/
public Closure getTrueClosure() {
return iTrueClosure;
}
Gets the closure called when false.
Returns: the closure Since: Commons Collections 3.1
/**
* Gets the closure called when false.
*
* @return the closure
* @since Commons Collections 3.1
*/
public Closure getFalseClosure() {
return iFalseClosure;
}
}