org.apache.commons.math.fraction.FractionField 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.math.fraction;
import java.io.Serializable;
import org.apache.commons.math.Field;
/**
* Representation of the fractional numbers field.
*
* This class is a singleton.
*
* @see Fraction
* @version $Revision: 811827 $ $Date: 2009-09-06 17:32:50 +0200 (dim. 06 sept. 2009) $
* @since 2.0
*/
public class FractionField implements Field, Serializable {
/** Serializable version identifier */
private static final long serialVersionUID = -1257768487499119313L;
/** Private constructor for the singleton.
*/
private FractionField() {
}
/** Get the unique instance.
* @return the unique instance
*/
public static FractionField getInstance() {
return LazyHolder.INSTANCE;
}
/** {@inheritDoc} */
public Fraction getOne() {
return Fraction.ONE;
}
/** {@inheritDoc} */
public Fraction getZero() {
return Fraction.ZERO;
}
// CHECKSTYLE: stop HideUtilityClassConstructor
/** Holder for the instance.
* We use here the Initialization On Demand Holder Idiom.
*/
private static class LazyHolder {
/** Cached field instance. */
private static final FractionField INSTANCE = new FractionField();
}
// CHECKSTYLE: resume HideUtilityClassConstructor
/** Handle deserialization of the singleton.
* @return the singleton instance
*/
private Object readResolve() {
// return the singleton instance
return LazyHolder.INSTANCE;
}
}