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* 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.collections4.functors;
import java.io.Serializable;
import org.apache.commons.collections4.Predicate;
import org.apache.commons.collections4.Transformer;
Predicate implementation that transforms the given object before invoking
another Predicate
.
Since: 3.1
/**
* Predicate implementation that transforms the given object before invoking
* another <code>Predicate</code>.
*
* @since 3.1
*/
public final class TransformedPredicate<T> implements PredicateDecorator<T>, Serializable {
Serial version UID /** Serial version UID */
private static final long serialVersionUID = -5596090919668315834L;
The transformer to call /** The transformer to call */
private final Transformer<? super T, ? extends T> iTransformer;
The predicate to call /** The predicate to call */
private final Predicate<? super T> iPredicate;
Factory to create the predicate.
Params: - transformer – the transformer to call
- predicate – the predicate to call with the result of the transform
Type parameters: - <T> – the type that the predicate queries
Throws: - NullPointerException – if the transformer or the predicate is null
Returns: the predicate
/**
* Factory to create the predicate.
*
* @param <T> the type that the predicate queries
* @param transformer the transformer to call
* @param predicate the predicate to call with the result of the transform
* @return the predicate
* @throws NullPointerException if the transformer or the predicate is null
*/
public static <T> Predicate<T> transformedPredicate(final Transformer<? super T, ? extends T> transformer,
final Predicate<? super T> predicate) {
if (transformer == null) {
throw new NullPointerException("The transformer to call must not be null");
}
if (predicate == null) {
throw new NullPointerException("The predicate to call must not be null");
}
return new TransformedPredicate<>(transformer, predicate);
}
Constructor that performs no validation.
Use transformedPredicate
if you want that.
Params: - transformer – the transformer to use
- predicate – the predicate to decorate
/**
* Constructor that performs no validation.
* Use <code>transformedPredicate</code> if you want that.
*
* @param transformer the transformer to use
* @param predicate the predicate to decorate
*/
public TransformedPredicate(final Transformer<? super T, ? extends T> transformer,
final Predicate<? super T> predicate) {
iTransformer = transformer;
iPredicate = predicate;
}
Evaluates the predicate returning the result of the decorated predicate
once the input has been transformed
Params: - object – the input object which will be transformed
Returns: true if decorated predicate returns true
/**
* Evaluates the predicate returning the result of the decorated predicate
* once the input has been transformed
*
* @param object the input object which will be transformed
* @return true if decorated predicate returns true
*/
@Override
public boolean evaluate(final T object) {
final T result = iTransformer.transform(object);
return iPredicate.evaluate(result);
}
Gets the predicate being decorated.
Returns: the predicate as the only element in an array Since: 3.1
/**
* Gets the predicate being decorated.
*
* @return the predicate as the only element in an array
* @since 3.1
*/
@Override
@SuppressWarnings("unchecked")
public Predicate<? super T>[] getPredicates() {
return new Predicate[] {iPredicate};
}
Gets the transformer in use.
Returns: the transformer
/**
* Gets the transformer in use.
*
* @return the transformer
*/
public Transformer<? super T, ? extends T> getTransformer() {
return iTransformer;
}
}