复数相加+equels、hashcode、clone<一>

 1 package com.jdk7.chapter1;
 2 
 3 public class ComplexNumber {
 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     public static void main(String[] args) {
62         ComplexNumber a = new ComplexNumber(1,2);
63 //        ComplexNumber a = new ComplexNumber();
64 //        ComplexNumber a = null;
65         ComplexNumber b = new ComplexNumber(1,2);
66 //        ComplexNumber b = new ComplexNumber();
67 //        ComplexNumber b = null;
68         // 被加数不能为null
69 //        System.out.println("(a+b) = "+a.add(b).toString());
70         
71         //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
72         System.out.println("(a==b) : "+a.equals(b));    
73         //对象实例内存地址不同，hashcode也不相同
74         System.out.println("hashcode of a: "+a.hashCode());
75         System.out.println("hashcode of b: "+b.hashCode());
76         try {
77             System.out.println(a.clone());
78         } catch (CloneNotSupportedException e) {
79             e.printStackTrace();
80         }
81         
82     }
83 
84 }