1 package com.jdk7.chapter1;
2
3 public class ComplexNumber implements Cloneable{
4
5 private double realPart;
6 private double imagePart;
7
8 public double getRealPart() {
9 return realPart;
10 }
11
12 public void setRealPart(double realPart) {
13 this.realPart = realPart;
14 }
15
16 public double getImagePart() {
17 return imagePart;
18 }
19
20 public void setImagePart(double imagePart) {
21 this.imagePart = imagePart;
22 }
23
24 @Override
25 public String toString() {
26 return "realPart=" + realPart + ", imagePart=" + imagePart + "i";
27 }
28
29 /**
30 * 默认构造函数
31 */
32 public ComplexNumber(){
33 this.realPart = 0.0;
34 this.imagePart = 0.0;
35 }
36
37 /**
38 * 自定义带参构造函数
39 * @param a
40 * @param b
41 */
42 public ComplexNumber(double a,double b){
43 this.realPart = a;
44 this.imagePart = b;
45 }
46
47 /**
48 * 复数相加
49 * 返回复数类型
50 * @return
51 */
52 public ComplexNumber add(ComplexNumber comn){
53 if(comn==null){
54 System.err.println("对象不能为null");
55 return new ComplexNumber();
56 }else{
57 return new ComplexNumber(this.realPart+comn.realPart,this.imagePart+comn.imagePart);
58 }
59 }
60
61 /**
62 * 实现Cloneable接口，将equal()重写
63 * 分为以下3中情况:
64 * 1.比较对象为空；
65 * 2.比较对象为被比较或者子类
66 * 2.1复数相等
67 * 2.2复数不等
68 * 3.比较对象不为被比较或者子类
69 */
70 public boolean equals(Object obj){
71 if(obj==null){
72 System.out.println("对象不能为空");
73 return false;
74 }else if(obj instanceof ComplexNumber){
75 ComplexNumber c = (ComplexNumber)obj;
76 if(this.realPart==c.realPart && this.imagePart==c.imagePart){
77 return true;
78 }else{
79 System.out.println("复数不相同");
80 return false;
81 }
82 }else{
83 System.out.println("对象不属于复数类型");
84 return false;
85 }
86 }
87
88 /**
89 * 如果两个对象的值是相同的->调用toString()方法转换为字符串也相同->再将字符串转换为hashcode则一定是相同的
90 */
91 public int hashCode(){
92 return this.toString().hashCode();
93 }
94
95 /**
96 * 一定要继承接口中的clone()方法，克隆一个自定义类型，并将被克隆对象的值赋给克隆对象
97 */
98 public ComplexNumber clone(){
99 try{
100 ComplexNumber d = (ComplexNumber)super.clone(); //继承接口的clone()方法,将Object类型强制转换为要克隆的类型
101 d.setRealPart(this.realPart);
102 d.setImagePart(this.imagePart);
103 return new ComplexNumber(d.realPart,d.imagePart);
104 }catch(CloneNotSupportedException e){
105 e.printStackTrace();
106 return null;
107 }
108 }
109
110 public static void main(String[] args) {
111 ComplexNumber a = new ComplexNumber(1,2);
112 // ComplexNumber a = new ComplexNumber();
113 // ComplexNumber a = null;
114 ComplexNumber b = new ComplexNumber(1,2);
115 // ComplexNumber b = new ComplexNumber(2,4);
116 // ComplexNumber b = new ComplexNumber();
117 // ComplexNumber b = null;
118 // ComplexNumber1 b = new ComplexNumber1();
119 // 被加数不能为null
120 // System.out.println("(a+b) = "+a.add(b).toString());
121
122 //a和b的值虽然相同，但是在声明为类类型变量时为不同的内存地址，object提供的equels方法比较的是内存地址
123 System.out.println("(a==b) : "+a.equals(b));
124 //对象实例内存地址不同，hashcode以对象实例在内存的地址生成hashcode也不相同
125 System.out.println("hashcode of a: "+a.hashCode());
126 System.out.println("hashcode of b: "+b.hashCode());
127 System.out.println("(a.hashCode==b.hashCode) = "+(a.hashCode()==b.hashCode()));
128 System.out.println("clone a: "+a.clone());
129
130 }
131
132 }
133
134
135 运行结果：
136 (a==b) : true
137 hashcode of a: 1012487935
138 hashcode of b: 1012487935
139 (a.hashCode==b.hashCode) = true
140 clone a: realPart=1.0, imagePart=2.0i
