重写equals()和hashCode()

 1 public class OrderElement {
 2 
 3     public OrderElement() {
 4     }
 5 
 6     public OrderElement(Integer orderNo, String propertyName, boolean isAsc) {
 7         this.orderNo = orderNo;
 8         this.propertyName = propertyName;
 9         this.isAsc = isAsc;
10     }
11 
12     private Integer orderNo;
13     private String propertyName;// 排序属性
14     private boolean isAsc;// 是否正序
15 
16     public Integer getOrderNo() {
17         return orderNo;
18     }
19 
20     public void setOrderNo(Integer orderNo) {
21         this.orderNo = orderNo;
22     }
23 
24     public String getPropertyName() {
25         return this.propertyName;
26     }
27 
28     public void setPropertyName(String propertyName) {
29         this.propertyName = propertyName;
30     }
31 
32     public boolean getIsAsc() {
33         return this.isAsc;
34     }
35 
36     public void setAsc(boolean isAsc) {
37         this.isAsc = isAsc;
38     }
39 
40     @Override
41     public boolean equals(Object obj) {
42         if (obj == null || !this.getClass().getName().equals(obj.getClass().getName()))
43             return false;
44         OrderElement e = OrderElement.class.cast(obj);
45         if (getPropertyName() != null && e.getPropertyName() != null && getPropertyName().equals(e.getPropertyName()))
46             return true;
47         return super.equals(obj);
48     }
49 
50     @Override
51     public int hashCode() {
52         if (getPropertyName() != null) {
53             return getPropertyName().hashCode();
54         }
55         return super.hashCode();
56     }
57 }