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* 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,
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* See the License for the specific language governing permissions and
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*/
package org.apache.commons.collections.functors;
import java.io.Serializable;
import org.apache.commons.collections.Predicate;
import org.apache.commons.collections.Transformer;
Transformer implementation that calls a Predicate using the input object
and then returns the input.
Author: Stephen Colebourne Since: Commons Collections 3.0 Version: $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
/**
* Transformer implementation that calls a Predicate using the input object
* and then returns the input.
*
* @since Commons Collections 3.0
* @version $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
*
* @author Stephen Colebourne
*/
public class PredicateTransformer implements Transformer, Serializable {
Serial version UID /** Serial version UID */
private static final long serialVersionUID = 5278818408044349346L;
The closure to wrap /** The closure to wrap */
private final Predicate iPredicate;
Factory method that performs validation.
Params: - predicate – the predicate to call, not null
Throws: - IllegalArgumentException – if the predicate is null
Returns: the predicate
transformer
/**
* Factory method that performs validation.
*
* @param predicate the predicate to call, not null
* @return the <code>predicate</code> transformer
* @throws IllegalArgumentException if the predicate is null
*/
public static Transformer getInstance(Predicate predicate) {
if (predicate == null) {
throw new IllegalArgumentException("Predicate must not be null");
}
return new PredicateTransformer(predicate);
}
Constructor that performs no validation.
Use getInstance
if you want that.
Params: - predicate – the predicate to call, not null
/**
* Constructor that performs no validation.
* Use <code>getInstance</code> if you want that.
*
* @param predicate the predicate to call, not null
*/
public PredicateTransformer(Predicate predicate) {
super();
iPredicate = predicate;
}
Transforms the input to result by calling a predicate.
Params: - input – the input object to transform
Returns: the transformed result
/**
* Transforms the input to result by calling a predicate.
*
* @param input the input object to transform
* @return the transformed result
*/
public Object transform(Object input) {
return (iPredicate.evaluate(input) ? Boolean.TRUE : Boolean.FALSE);
}
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;
}
}