com.feilong.lib.collection4.functors.NullIsTruePredicate Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of feilong Show documentation
Show all versions of feilong Show documentation
feilong is a suite of core and expanded libraries that include utility classes, http, excel,cvs, io classes, and much much more.
/*
* 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 com.feilong.lib.collection4.functors;
import java.io.Serializable;
import org.apache.commons.collections4.Predicate;
/**
* Predicate implementation that returns true if the input is null.
*
* @param
*
* @since 3.0
*/
public final class NullIsTruePredicate implements PredicateDecorator,Serializable{
/** Serial version UID */
private static final long serialVersionUID = -7625133768987126273L;
/** The predicate to decorate */
private final Predicate iPredicate;
/**
* Factory to create the null true predicate.
*
* @param
* the type that the predicate queries
* @param predicate
* the predicate to decorate, not null
* @return the predicate
* @throws NullPointerException
* if the predicate is null
*/
public static Predicate nullIsTruePredicate(final Predicate predicate){
if (predicate == null){
throw new NullPointerException("Predicate must not be null");
}
return new NullIsTruePredicate<>(predicate);
}
/**
* Constructor that performs no validation.
* Use nullIsTruePredicate
if you want that.
*
* @param predicate
* the predicate to call after the null check
*/
public NullIsTruePredicate(final Predicate predicate){
super();
iPredicate = predicate;
}
/**
* Evaluates the predicate returning the result of the decorated predicate
* once a null check is performed.
*
* @param object
* the input object
* @return true if decorated predicate returns true or input is null
*/
@Override
public boolean evaluate(final T object){
if (object == null){
return true;
}
return iPredicate.evaluate(object);
}
/**
* Gets the predicate being decorated.
*
* @return the predicate as the only element in an array
* @since 3.1
*/
@Override
@SuppressWarnings("unchecked")
public Predicate[] getPredicates(){
return new Predicate[] { iPredicate };
}
}