关于Java clone（浅克隆） 的代码

import java.util.Date;

public class HelloWorld{
    public static void main(String[] args) throws CloneNotSupportedException{
        Student stu1 = new Student();
        Student stu2 = (Student)stu1.clone(stu1);
        
        System.out.println(stu1);
        System.out.println(stu2);
        System.out.println(stu1 == stu2);
        System.out.println(stu1.createDate == stu2.createDate);
        
        stu2.createDate = new Date();
        stu2.name = "TomCat";
        stu2.age = 2333;
        
        System.out.println(stu1);
        System.out.println(stu2);
        
        System.out.println(stu1.createDate == stu2.createDate);
        
    }
}
class Student implements Cloneable {
    public Date createDate = new Date();
    public String name;
    public int age;
    
    public Student() {
        this("Stupid", 18);
    }
    
    public Student(String name, int age) {
        this.name = name;
        this.age = age;
    }
    
    public Object clone(Object o) throws CloneNotSupportedException {
        return super.clone();
    }

    @Override
    public String toString() {
        return "Student [createDate=" + createDate + ", name=" + name + ", age=" + age + "]";
    }
}

Student [createDate=Fri Jul 28 19:46:06 CST 2017, name=Stupid, age=18]
Student [createDate=Fri Jul 28 19:46:06 CST 2017, name=Stupid, age=18]
false
true
Student [createDate=Fri Jul 28 19:46:06 CST 2017, name=Stupid, age=18]
Student [createDate=Fri Jul 28 19:46:06 CST 2017, name=TomCat, age=2333]
false

new Date(); 是有创建了一个对象 其引用是是stu2.createDate 

QAQ 我错了，我错了，我错了，我错了

应该写成下面样子

stu2.createDate.setYear(1900);

Student [createDate=Fri Jul 28 19:51:05 CST 2017, name=Stupid, age=18]
Student [createDate=Fri Jul 28 19:51:05 CST 2017, name=Stupid, age=18]
false
true
Student [createDate=Mon Jul 28 19:51:05 CST 3800, name=Stupid, age=18]
Student [createDate=Mon Jul 28 19:51:05 CST 3800, name=TomCat, age=2333]
true

所以clone方法是一个浅克隆

QAQ

加一个图片解释一下