Raymond | dee0849 | 2015-04-02 10:43:13 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Licensed to the Apache Software Foundation (ASF) under one or more |
| 3 | * contributor license agreements. See the NOTICE file distributed with |
| 4 | * this work for additional information regarding copyright ownership. |
| 5 | * The ASF licenses this file to You under the Apache License, Version 2.0 |
| 6 | * (the "License"); you may not use this file except in compliance with |
| 7 | * the License. You may obtain a copy of the License at |
| 8 | * |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | * |
| 11 | * Unless required by applicable law or agreed to in writing, software |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | * See the License for the specific language governing permissions and |
| 15 | * limitations under the License. |
| 16 | */ |
| 17 | |
| 18 | package org.apache.commons.math.util; |
| 19 | |
| 20 | import java.io.Serializable; |
| 21 | |
| 22 | import org.apache.commons.math.Field; |
| 23 | |
| 24 | /** |
| 25 | * Representation of real numbers with arbitrary precision field. |
| 26 | * <p> |
| 27 | * This class is a singleton. |
| 28 | * </p> |
| 29 | * @see BigReal |
| 30 | * @version $Revision: 811827 $ $Date: 2009-09-06 17:32:50 +0200 (dim. 06 sept. 2009) $ |
| 31 | * @since 2.0 |
| 32 | */ |
| 33 | public class BigRealField implements Field<BigReal>, Serializable { |
| 34 | |
| 35 | /** Serializable version identifier */ |
| 36 | private static final long serialVersionUID = 4756431066541037559L; |
| 37 | |
| 38 | /** Private constructor for the singleton. |
| 39 | */ |
| 40 | private BigRealField() { |
| 41 | } |
| 42 | |
| 43 | /** Get the unique instance. |
| 44 | * @return the unique instance |
| 45 | */ |
| 46 | public static BigRealField getInstance() { |
| 47 | return LazyHolder.INSTANCE; |
| 48 | } |
| 49 | |
| 50 | /** {@inheritDoc} */ |
| 51 | public BigReal getOne() { |
| 52 | return BigReal.ONE; |
| 53 | } |
| 54 | |
| 55 | /** {@inheritDoc} */ |
| 56 | public BigReal getZero() { |
| 57 | return BigReal.ZERO; |
| 58 | } |
| 59 | |
| 60 | // CHECKSTYLE: stop HideUtilityClassConstructor |
| 61 | /** Holder for the instance. |
| 62 | * <p>We use here the Initialization On Demand Holder Idiom.</p> |
| 63 | */ |
| 64 | private static class LazyHolder { |
| 65 | /** Cached field instance. */ |
| 66 | private static final BigRealField INSTANCE = new BigRealField(); |
| 67 | } |
| 68 | // CHECKSTYLE: resume HideUtilityClassConstructor |
| 69 | |
| 70 | /** Handle deserialization of the singleton. |
| 71 | * @return the singleton instance |
| 72 | */ |
| 73 | private Object readResolve() { |
| 74 | // return the singleton instance |
| 75 | return LazyHolder.INSTANCE; |
| 76 | } |
| 77 | |
| 78 | } |