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/*
* ============LICENSE_START=======================================================
* ONAP
* ================================================================================
* Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
* ================================================================================
* Licensed 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.
* ============LICENSE_END=========================================================
*/
package org.onap.policy.drools.utils;
/**
* Reference to an object. Used within functional methods, where thread-safety is not
* required.
*
* @param <T> type of object contained within the reference
*/
public class Reference<T> {
private T value;
/**
*
* @param value
*/
public Reference(T value) {
this.value = value;
}
/**
* @return the current value
*/
public final T get() {
return value;
}
/**
* Sets the reference to point to a new value.
*
* @param newValue
*/
public final void set(T newValue) {
this.value = newValue;
}
/**
* Sets the value to a new value, if the value is currently the same as the old value.
*
* @param oldValue
* @param newValue
* @return {@code true} if the value was updated, {@code false} otherwise
*/
public boolean compareAndSet(T oldValue, T newValue) {
if (value == oldValue) {
value = newValue;
return true;
} else {
return false;
}
}
}
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