HashMap的key的有关问题

import java.util.HashMap;import java.util.Map;class Dog{    public String name;    public Dog(String name){        this.name = name;    }    public boolean equals(Object o){        if((o instanceof Dog) && (((Dog)o).name == name)){            return true;        }else{            return false;        }    }    public int hashCode(){        return name.length();    }    public String toString(){        return name;    }}public class Test111226{    public static void main(String[] args) {        Map<Object, Object> m = new HashMap<Object, Object>();        Dog d1 = new Dog("clover");        m.put(d1, "DDDDOG");        System.out.println(m.get(d1));        d1.name = "magnolia";        for(Object o: m.keySet()){            System.out.println(o.hashCode());            System.out.println(o.toString());        }        System.out.println("================");        System.out.println(d1.hashCode());        System.out.println(d1.toString());        System.out.println("----------------");        System.out.println(m.get(d1));            }}