如何制作一个对象的深层复制，在java中的对象内部引用其类型

Question

如何对一个对象进行深度复制，该对象在java中的对象内引用了它的类型

public class Employee implements Cloneable {
    private String Lastname;
    private String Firstname;
    private Employee supervisor;
    private Employee staff[];
    @Override
    protected Object clone() throws CloneNotSupportedException {
        Employee copy = (Employee) super.clone();
        copy.supervisor = (Employee)supervisor.clone();
        copy.staff = staff.clone();
        return copy;
    }
}