??????????hashmap????get???????????????hashcdoe???????????????????????Щ?????????????hashcode????????????????С?????????????????洢????????п??????????hashcode??????????????get??????for?????????У???????null??
???????????????????????????“1”?????????????дhashCode????????equals??????hashCode???????????????????????

package com.cxh.test1;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Set;
class People{
private String name;
private int age;
public People(String name??int age) {
this.name = name;
this.age = age;
}
public void setAge(int age){
this.age = age;
}
@Override
public int hashCode() {
// TODO Auto-generated method stub
return name.hashCode()*37+age;
}
@Override
public boolean equals(Object obj) {
// TODO Auto-generated method stub
return this.name.equals(((People)obj).name) && this.age== ((People)obj).age;
}
}
public class Main {
public static void main(String[] args) {
People p1 = new People("Jack"?? 12);
System.out.println(p1.hashCode());
HashMap<People?? Integer> hashMap = new HashMap<People?? Integer>();
hashMap.put(p1?? 1);
System.out.println(hashMap.get(new People("Jack"?? 12)));
}
}
???????????????????????“1”???