修改了key之后不能remove

class Student implements Serializable {
        Integer id;
        String name;

        public Student(Integer id, String name) {
            this.id = id;
            this.name = name;
        }

        public Student() {
        }

        //getter,setter....

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;
            Student student = (Student) o;
            return Objects.equals(getId(), student.getId()) &&
                    Objects.equals(getName(), student.getName());
        }

        @Override
        public int hashCode() {
            return Objects.hash(getId(), getName());
        }
    }
        Map<Student,Integer> map=new HashMap<>(4);
        Student stu1=new Student(1,"zs"),stu2=new Student(2,"ls");
        map.put(stu1,1);
        map.put(stu2,2);
        stu1.setName("hhh");
        map.remove(stu1);
        for (Student student : map.keySet()) {
            System.out.println(student);
        }class Student implements Seri