在Java中，對象克隆分為深克隆和淺克隆兩種類型。深克隆指的是將一個對象完整地復(fù)制，包括它的所有屬性，而淺克隆則只是復(fù)制了對象本身，其屬性還是由原對象共用。

深克隆一般有兩種實現(xiàn)方式，即使用重寫Object類的clone方法和使用序列化反序列化的方式。

/**
 * 重寫Object類的clone方法實現(xiàn)深克隆
 */
public class Person implements Cloneable{
private String name;
private Address address;
public Person(String name, Address address) {
this.name = name;
this.address = address;
}
@Override
public Object clone() throws CloneNotSupportedException {
Person person = (Person) super.clone();
person.address = (Address) address.clone();
return person;
}
//getters and setters
}
public class Address implements Cloneable{
private String city;
private String street;
public Address(String city, String street) {
this.city = city;
this.street = street;
}
@Override
public Object clone() throws CloneNotSupportedException {
return super.clone();
}
//getters and setters
}
//使用
Address address = new Address("Beijing", "Chaoyang");
Person person1 = new Person("John", address);
Person person2 = (Person) person1.clone();
System.out.println(person1 == person2); //false
System.out.println(person1.getAddress() == person2.getAddress()); //false

從上述代碼中可以看出，當(dāng)我們想要實現(xiàn)深克隆時，需要將實例化對象中的所有引用類型的屬性進行克隆，即使用該類型的clone方法進行克隆，而如果該類型沒有實現(xiàn)Cloneable接口，則必須手動書寫clone方法。

而淺克隆則較為簡單，只需要在對象上實現(xiàn)Cloneable接口即可，但是需要注意的是，克隆出來的對象并沒有完全獨立于原對象，它們還會共享一些屬性。

/**
 * 實現(xiàn)Cloneable接口的對象實現(xiàn)淺克隆
 */
public class Computer implements Cloneable{
private String brand;
private String model;
private Memory memory;
public Computer(String brand, String model, Memory memory) {
this.brand = brand;
this.model = model;
this.memory = memory;
}
public Object clone() throws CloneNotSupportedException {
return super.clone();
}
//getters and setters
}
public class Memory{
private int size;
public Memory(int size) {
this.size = size;
}
//getters and setters
}
//使用
Memory memory = new Memory(16);
Computer computer1 = new Computer("Apple", "MacBook Pro", memory);
Computer computer2 = (Computer) computer1.clone();
System.out.println(computer1 == computer2); //false
System.out.println(computer1.getMemory() == computer2.getMemory()); //true

從上述代碼中可以看出，淺克隆出來的對象始終還會共享一些屬性，上述代碼中computer1和computer2共用了同一個Memory對象。