Java深拷贝和浅拷贝的区别

浅拷贝

被复制的对象的所有的变量都与原对象有相同的值，而所有的引用对象仍然指向原来的对象。换言之，浅拷贝 不复制引用对象。

 1 class Experience {
 2     private String skill;
 3     public void setSkill(String skill){
 4         this.skill = skill;
 5     }
 6     public void setExperience(String skill){
 7         this.skill = skill;
 8     }
 9
10     @Override
11     public String toString() {
12         return skill;
13     }
14 }
15
16 public class CloneTest implements Cloneable{
17
18     private int age ;
19     private Experience experience;
20
21     public CloneTest(){
22         this.age = 10;
23         this.experience = new Experience();
24     }
25     public Experience getExperience() {
26         return experience;
27     }
28     public void setExperience(String skill){
29         experience.setExperience(skill);
30     }
31     public void show(){
32         System.out.println(experience.toString());
33     }
34     public int getAge() {
35         return age;
36     }
37     @Override
38     protected Object clone() throws CloneNotSupportedException {
39         return (CloneTest) super.clone();
40     }
41 }
42 //测试类
43 class MianTest{
44
45     public static void main(String[] args) throws CloneNotSupportedException {
46         CloneTest test = new CloneTest();
47         test.setExperience("我是小明，我精通Java，C++的复制粘贴");
48         test.show();
49         CloneTest cloneTest = (CloneTest) test.clone();
50         cloneTest.show();
51         cloneTest.setExperience("我是小明的副本，我精通Java,C++");
52         cloneTest.show();
53         test.show();
54         System.out.println(cloneTest.getAge());
55     }
56 }

输出的结果：

我是小明，我精通Java，C++的复制粘贴

我是小明，我精通Java，C++的复制粘贴

我是小明的副本，我精通Java,C++

我是小明的副本，我精通Java,C++

10

从结果中不难看出，拷贝的副本改变了Experience的skill属性，原类中的skill属性打印出来也是修改后的结果，说明引用 类型的拷贝没有将对象拷贝，引用的指向还是原类中的指向

深拷贝

除了被复制的对象的所有变量都有原来对象的值之外，还把引用对象也指向了被复制的新对象

 1 class Experience implements Cloneable{
 2     private String skill;
 3     public void setSkill(String skill){
 4         this.skill = skill;
 5     }
 6     public void setExperience(String skill){
 7         this.skill = skill;
 8     }
 9
10     @Override
11     public String toString() {
12         return skill;
13     }
14
15     @Override
16     protected Object clone() throws CloneNotSupportedException {
17         return super.clone();
18     }
19 }
20
21 public class CloneTest implements Cloneable{
22
23     private int age ;
24     private Experience experience;
25
26     public CloneTest(){
27         this.age = 10;
28         this.experience = new Experience();
29     }
30     public Experience getExperience() {
31         return experience;
32     }
33     public void setExperience(String skill){
34         experience.setExperience(skill);
35     }
36     public void show(){
37         System.out.println(experience.toString());
38     }
39     public int getAge() {
40         return age;
41     }
42     @Override
43     protected Object clone() throws CloneNotSupportedException {
44         CloneTest o = (CloneTest) super.clone();
45         o.experience = (Experience) o.getExperience().clone();
46         return o;
47     }
48 }
49 class MianTest{
50
51     public static void main(String[] args) throws CloneNotSupportedException {
52         CloneTest test = new CloneTest();
53         test.setExperience("我是小明，我精通Java，C++的复制粘贴");
54         test.show();
55         CloneTest cloneTest = (CloneTest) test.clone();
56         cloneTest.show();
57         cloneTest.setExperience("我是小明的副本，我精通Java,C++");
58         cloneTest.show();
59         test.show();
60         System.out.println(cloneTest.getAge());
61     }
62 }

输出的结果：

我是小明，我精通Java，C++的复制粘贴

我是小明，我精通Java，C++的复制粘贴

我是小明的副本，我精通Java,C++

我是小明，我精通Java，C++的复制粘贴

10

可以看出和第一次的结果不同了。

o.experience =(Experience) o.getExperience().clone();

加了这句之后效果不同的。说明实现了深拷贝，原引用对象也复制过来了