Java shallow clone and deep clone

What are shallow clones and deep clones?

克隆顾名思义就是，参照一个东西再做一个出来浅克隆：直接复写Object的clone()方法，默认情况下8种基本数据类型和String都会进行深克隆，另外的其他引用类型为浅克隆（浅克隆：引用指向的是同一个对象）深克隆：浅克隆中那另外的其他引用类型都让其变为深克隆

Reference type plots

Shallow clone

public class Main {    public static void main(String[] args) throws Exception {        A a = new A();        A b = (A)a.clone();        b.str = "....";        b.i = 1000;        System.out.println(a == b); //false 表示地址并不一样，不是同一个引用        System.out.println(a.p == b.p); //true 表示引用类型只想的是同一个引用        System.out.println(a.str == b.str); //false 表示地址并不一样，不是同一个引用        System.out.println(a.i == b.i);    //false 表示地址并不一样，不是同一个引用    }}//克隆对象需要实现Cloneable接口class A implements Cloneable {    Person p = new Person("谭迪");    String str = "hehe";    int i = 100;    //浅克隆：该方法来自于Object    @Override    protected Object clone() throws CloneNotSupportedException {        return super.clone();    }}class Person{    String name;    public Person(String name) {        this.name = name;    }}

Deep clones

public class Main {    public static void main(String[] args) throws Exception {        A a = new A();        A b = (A)a.clone();        b.str = "....";        b.i = 1000;                System.out.println(a == b);         //false        System.out.println(a.p == b.p);     //flase        System.out.println(a.str == b.str); //flase        System.out.println(a.i == b.i);     //flase    }}//克隆对象需要实现Cloneable接口class A implements Cloneable {    Person p = new Person("小明");    String str = "hehe";    int i = 100;    //深克隆：该方法来自于Object    @Override    protected A clone() throws CloneNotSupportedException {        A a = (A)super.clone();        a.p = (Person)p.clone();        return a;    }}class Person implements Cloneable{    String name;    public Person(String name) { this.name = name; }    @Override    protected Object clone() throws CloneNotSupportedException {        return super.clone();    }}

Java shallow clone and deep clone