在Java中，對象的克隆一般分為淺克隆和深度克隆。

淺克隆指的是一個對象通過clone()方法復制自身，但并不會復制引用的對象，而是將這些引用直接指向原來的對象。

class Person implements Cloneable {
private String name;
private Address address;
//省略構造方法和getter/setter方法
@Override
public Person clone() throws CloneNotSupportedException {
return (Person) super.clone();
}
}
class Address {
private String city;
private String street;
//省略構造方法和getter/setter方法
}
public static void main(String[] args) throws CloneNotSupportedException {
// original Person
Person person = new Person("Tom", new Address("Beijing", "Main Street"));
// clone Person
Person clone = person.clone();
// change clone's Address
clone.getAddress().setCity("Shanghai");
System.out.println(person.getAddress().getCity()); // 輸出 Shanghai
}

可以看到，當我們修改clone對象中的address時，原對象person的address也被修改了，這是因為clone對象和原對象的address引用指向的是同一個對象。

深度克隆則是將對象的引用對象也進行克隆，使得新克隆的對象和原對象完全獨立。

class Person implements Cloneable {
private String name;
private Address address;
//省略構造方法和getter/setter方法
@Override
public Person clone() throws CloneNotSupportedException {
Person clone = (Person) super.clone();
clone.setAddress(this.address.clone());
return clone;
}
}
class Address implements Cloneable {
private String city;
private String street;
//省略構造方法和getter/setter方法
@Override
public Address clone() throws CloneNotSupportedException {
return (Address) super.clone();
}
}
public static void main(String[] args) throws CloneNotSupportedException {
// original Person
Person person = new Person("Tom", new Address("Beijing", "Main Street"));
// clone Person
Person clone = person.clone();
// change clone's Address
clone.getAddress().setCity("Shanghai");
System.out.println(person.getAddress().getCity()); // 輸出 Beijing
}

可以看到，當我們修改clone對象中的address時，原對象person的address并沒有被修改，這是因為clone對象和原對象的address引用指向的是不同的對象。