使用Serializable接口，实现深度克隆

  1 package clone.serializable;
  2 
  3 import java.io.*;
  4 
  5 public class MyUtil {
  6     private MyUtil() {
  7         throw new AssertionError();
  8     }
  9 
 10     @SuppressWarnings("unchecked")
 11     public static <T extends Serializable> T clone(T obj) throws Exception {
 12         ByteArrayOutputStream bout = new ByteArrayOutputStream();
 13         ObjectOutputStream oos = new ObjectOutputStream(bout);
 14         oos.writeObject(obj);
 15         ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
 16         ObjectInputStream ois = new ObjectInputStream(bin);
 17         return (T) ois.readObject();
 18         // 说明：调用 ByteArrayInputStream 或 ByteArrayOutputStream 对象的 close 方法没有任何意义
 19         // 这两个基于内存的流只要垃圾回收器清理对象就能够释放资源，这 一点不同于对外部资源（如文件流）的释放
 20     }
 21 }
 22 
 23 package clone.serializable;
 24 
 25 import java.io.Serializable;
 26 
 27 public class Car implements Serializable {
 28 
 29     private static final long serialVersionUID = -5713945027627603702L;
 30     // 品牌
 31     private String brand;
 32     // 最高时速
 33     private int maxSpeed;
 34     public Car(String brand, int maxSpeed) {
 35         this.brand = brand;
 36         this.maxSpeed = maxSpeed;
 37     }
 38     public String getBrand() {
 39         return brand;
 40     }
 41     public void setBrand(String brand) {
 42         this.brand = brand;
 43     }
 44     public int getMaxSpeed() {
 45         return maxSpeed;
 46     }
 47     public void setMaxSpeed(int maxSpeed) {
 48         this.maxSpeed = maxSpeed;
 49     }
 50     @Override public String toString() {
 51         return "Car [brand=" + brand + ", maxSpeed=" + maxSpeed + "]";
 52     }
 53 }
 54 
 55 
 56 package clone.serializable;
 57 
 58 import java.io.Serializable;
 59 
 60 public class Person implements Serializable {
 61     private static final long serialVersionUID = -9102017020286042305L;
 62     // 姓名
 63     private String name;
 64     // 年龄
 65     private int age;
 66     // 座驾
 67     private Car car;
 68 
 69     public Person(String name, int age, Car car) {
 70         this.name = name; this.age = age; this.car = car;
 71     }
 72     public String getName() {
 73         return name;
 74     }
 75     public void setName(String name) {
 76         this.name = name;
 77     }
 78     public int getAge() {
 79         return age;
 80     }
 81     public void setAge(int age) {
 82         this.age = age;
 83     }
 84     public Car getCar() {
 85         return car;
 86     }
 87     public void setCar(Car car) {
 88         this.car = car;
 89     }
 90     @Override public String toString() {
 91         return "Person [name=" + name + ", age=" + age + ", car=" + car + "]";
 92     }
 93 }
 94 
 95 
 96 package clone.serializable;
 97 
 98 public class CloneTest {
 99     public static void main(String[] args) {
100         try {
101             Person p1 = new Person("Hao LUO", 33, new Car("Benz", 300));
102             Person p2 = MyUtil.clone(p1);
103             // 深度克隆
104             p2.getCar().setBrand("BYD");
105             // 修改克隆的 Person 对象 p2 关联的汽车对象的品牌属性
106             // 原来的 Person 对象 p1 关联的汽车不会受到任何影响
107             // 因为在克隆 Person 对象时其关联的汽车对象也被克隆了
108             System.out.println(p1);
109             System.out.println(p2);
110         }catch (Exception e) {
111             e.printStackTrace();
112         }
113     }
114 }