1 package com.guanmu.test;
  2
  3
  4 /**
  5  * <p>
  6  * 类描述:
  7  * <p>
  8  *
  9  * 所属插件:com.guanmu.test
 10  *
 11  * @author guanmu 2015-10-20
 12  *
 13  */
 14 public class Model {
 15
 16     private String name;
 17     private String age;
 18     private String otherName;
 19
 20     /**
 21      * @param name
 22      * @param age
 23      * @param otherName
 24      */
 25     public Model(String name, String age, String otherName) {
 26         super();
 27         this.name = name;
 28         this.age = age;
 29         this.otherName = otherName;
 30     }
 31
 32     /**
 33      * @return the name
 34      */
 35     public String getName() {
 36         return name;
 37     }
 38
 39     /**
 40      * @param name
 41      *            the name to set
 42      */
 43     public void setName(String name) {
 44         this.name = name;
 45     }
 46
 47     /**
 48      * @return the age
 49      */
 50     public String getAge() {
 51         return age;
 52     }
 53
 54     /**
 55      * @param age
 56      *            the age to set
 57      */
 58     public void setAge(String age) {
 59         this.age = age;
 60     }
 61
 62     /**
 63      * @return the otherName
 64      */
 65     public String getOtherName() {
 66         return otherName;
 67     }
 68
 69     /**
 70      * @param otherName
 71      *            the otherName to set
 72      */
 73     public void setOtherName(String otherName) {
 74         this.otherName = otherName;
 75     }
 76
 77     @Override
 78     public int hashCode() {
 79
 80         int a = 7;
 81         int b = 11;
 82         // a和b为不相等的int型常量
 83         int r = a;
 84         r = r*b + name.hashCode();
 85         r = r*b + age.hashCode();
 86
 87 //        return r;
 88         return super.hashCode();
 89     }
 90
 91     @Override
 92     public boolean equals(Object obj) {
 93         if (!(obj instanceof Model)) {
 94             return false;
 95         }
 96
 97         Model other = (Model) obj;
 98         if (name.equals(other.getName()) && age.equals(other.getAge())) {
 99             return true;
100         }
101
102         return false;
103     }
104
105     /* (non-Javadoc)
106      * @see java.lang.Object#toString()
107      */
108     @Override
109     public String toString() {
110         return "Model [name=" + name + ", age=" + age + ", otherName=" + otherName + "]";
111     }
112
113
114 }

 1 package com.guanmu.test;
 2
 3 import java.util.ArrayList;
 4 import java.util.HashSet;
 5 import java.util.List;
 6 import java.util.Set;
 7
 8 /**
 9  * <p>
10  * 类描述:
11  * <p>
12  *
13  * 所属插件:com.guanmu.test
14  * @author guanmu2015-10-20
15  *
16  */
17 public class EqualsTest {
18
19
20
21     public static void main(String[] args) {
22         test1();
23         test2();
24     }
25
26     public static void test1() {
27         System.out.println("####:test1");
28         List<Model> list = new ArrayList<Model>();
29
30         Model a = new Model("a", "20", "test");
31         Model b = new Model("a","20","abcdef");
32         Model c = new Model("a","20","");
33
34         list.add(a);
35         System.out.println("a-hashCode:" + a.hashCode());
36         System.out.println(list);
37         if (!list.contains(b)) {
38             list.add(b);
39             System.out.println("b-hc:" + b.hashCode());
40             System.out.println(list);
41         }
42
43     }
44
45     public static void test2() {
46         System.out.println("####:test2");
47         Set<Model> set = new HashSet<Model>();
48
49         Model a = new Model("a", "20", "test");
50         Model b = new Model("a","20","abcdef");
51         Model c = new Model("a","20","");
52
53         set.add(a);
54         System.out.println("a-hashCode:" + a.hashCode());
55         System.out.println(set);
56         if (!set.contains(b)) {
57             set.add(b);
58             System.out.println("b-hc:" + b.hashCode());
59             System.out.println(set);
60         }
61
62     }
63 }