package com.datastruct.order;
import java.util.HashMap;
import java.util.Map;
public class TestHash {
public static void main(String[] args) {
MyObject my1 = new MyObject("xczxczx","xczxczxcx");
MyObject my2 = new MyObject("xczxczx","xczxczxcx");
Map<MyObject,String> map = new HashMap<MyObject,String>();
map.put(my1,"ssssss");
map.put(my2,"dddddd");
System.out.println(map.get(my1));
System.out.println(map.get(my2));
}
}
class MyObject{
private String name;
private String password;
public MyObject(String name,String password){
// TODO Auto-generated constructor stub
this.name = name;
this.password = password;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
@Override
public boolean equals(Object myObject){
if(this == myObject)
return true;
if (!(myObject instanceof MyObject)) {
return false;
}
MyObject p = (MyObject) myObject;
return p.getName() == ((MyObject) myObject).getName() && p.getPassword() == ((MyObject) myObject).getPassword();
}
@Override
public int hashCode(){
//31是一个奇素数,有个很好的特性,乘法可以优化为移位和减法:31*i==(i<<5)-i。
//现在的VM可以自动完成这种优化。习惯上都使用素数来计算散列结果
int result = name.hashCode();
result = 31 * result + password.hashCode();
System.out.println(result);
return result;
}
}
重写equals和hashcode方法
最新推荐文章于 2024-01-23 15:15:25 发布