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 * https://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 /* 19 * This is not the original file distributed by the Apache Software Foundation 20 * It has been modified by the Hipparchus project 21 */ 22 23 package org.hipparchus.complex; 24 25 import java.io.Serializable; 26 27 import org.hipparchus.Field; 28 29 /** 30 * Representation of the complex numbers field. 31 * <p> 32 * This class is a singleton. 33 * 34 * @see Complex 35 */ 36 public class ComplexField implements Field<Complex>, Serializable { 37 38 /** Serializable version identifier. */ 39 private static final long serialVersionUID = 20160305L; 40 41 /** Private constructor for the singleton. 42 */ 43 private ComplexField() { 44 } 45 46 /** Get the unique instance. 47 * @return the unique instance 48 */ 49 public static ComplexField getInstance() { 50 return LazyHolder.INSTANCE; 51 } 52 53 /** {@inheritDoc} */ 54 @Override 55 public Complex getOne() { 56 return Complex.ONE; 57 } 58 59 /** {@inheritDoc} */ 60 @Override 61 public Complex getZero() { 62 return Complex.ZERO; 63 } 64 65 /** {@inheritDoc} */ 66 @Override 67 public Class<Complex> getRuntimeClass() { 68 return Complex.class; 69 } 70 71 /** {@inheritDoc} */ 72 @Override 73 public boolean equals(final Object other) { 74 return this == other; 75 } 76 77 /** {@inheritDoc} */ 78 @Override 79 public int hashCode() { 80 return 0x49250ae5; 81 } 82 83 // CHECKSTYLE: stop HideUtilityClassConstructor 84 /** Holder for the instance. 85 * <p>We use here the Initialization On Demand Holder Idiom.</p> 86 */ 87 private static class LazyHolder { 88 /** Cached field instance. */ 89 private static final ComplexField INSTANCE = new ComplexField(); 90 } 91 // CHECKSTYLE: resume HideUtilityClassConstructor 92 93 /** Handle deserialization of the singleton. 94 * @return the singleton instance 95 */ 96 private Object readResolve() { 97 // return the singleton instance 98 return LazyHolder.INSTANCE; 99 } 100 101 }