org.apache.commons.collections4.functors.EqualPredicate Maven / Gradle / Ivy
/*
* 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.Equator;
import org.apache.commons.collections4.Predicate;
/**
* Predicate implementation that returns true if the input is the same object
* as the one stored in this predicate by equals.
*
* @since 3.0
*/
public final class EqualPredicate implements Predicate, Serializable {
/** Serial version UID */
private static final long serialVersionUID = 5633766978029907089L;
/** The value to compare to */
private final T iValue;
/** The equator to use for comparison */
private final Equator equator;
/**
* Factory to create the predicate.
*
* @param the type that the predicate queries
* @param object the object to compare to
* @return the predicate
*/
public static Predicate equalPredicate(final T object) {
if (object == null) {
return NullPredicate.nullPredicate();
}
return new EqualPredicate<>(object);
}
/**
* Factory to create the identity predicate.
*
* @param the type that the predicate queries
* @param object the object to compare to
* @param equator the equator to use for comparison
* @return the predicate
* @since 4.0
*/
public static Predicate equalPredicate(final T object, final Equator equator) {
if (object == null) {
return NullPredicate.nullPredicate();
}
return new EqualPredicate<>(object, equator);
}
/**
* Constructor that performs no validation.
* Use equalPredicate if you want that.
*
* @param object the object to compare to
*/
public EqualPredicate(final T object) {
// do not use the DefaultEquator to keep backwards compatibility
// the DefaultEquator returns also true if the two object references are equal
this(object, null);
}
/**
* Constructor that performs no validation.
* Use equalPredicate if you want that.
*
* @param object the object to compare to
* @param equator the equator to use for comparison
* @since 4.0
*/
public EqualPredicate(final T object, final Equator equator) {
super();
iValue = object;
this.equator = equator;
}
/**
* Evaluates the predicate returning true if the input equals the stored value.
*
* @param object the input object
* @return true if input object equals stored value
*/
@Override
public boolean evaluate(final T object) {
if (equator != null) {
return equator.equate(iValue, object);
}
return iValue.equals(object);
}
/**
* Gets the value.
*
* @return the value
* @since 3.1
*/
public Object getValue() {
return iValue;
}
}