重写equals与hashCode方法比较Set集合的对象

public class DamoTest {
    public static void main(String[] args){
        Student student1=new Student("李华",11,"男");
        Student student2=new Student("李华",11,"男");
        student1.hashCode();
        student2.hashCode();
        HashSet<Student>studentHashSet=new HashSet<>();
        studentHashSet.add(student1);
        studentHashSet.add(student2);
        System.out.println(studentHashSet.size());//1
    }
}
class Student{
    private String name;
    private int age;
    private String sex;

    public Student() {
    }

    public Student(String name, int age, String sex) {
        this.name = name;
        this.age = age;
        this.sex = sex;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

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

    @Override
    public int hashCode() {
        return Objects.hash(name, age, sex);
    }