如何实现对象克隆？

有两种方式：
1). 实现Cloneable接口并重写Object类中的clone()方法；
2). 实现Serializable接口，通过对象的序列化和反序列化实现克隆，可以实现真正的深度克隆，代码如下。

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import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.ObjectInputStream; import java.io.ObjectOutputStream;   public class MyUtil {       private MyUtil() {         throw new AssertionError();     }       public static <T> T clone(T obj) throws Exception {         ByteArrayOutputStream bout = new ByteArrayOutputStream();         ObjectOutputStream oos = new ObjectOutputStream(bout);         oos.writeObject(obj);           ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());         ObjectInputStream ois = new ObjectInputStream(bin);         return (T) ois.readObject();           // 说明：调用ByteArrayInputStream或ByteArrayOutputStream对象的close方法没有任何意义         // 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     } }

下面是测试代码：

 

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import java.io.Serializable;   /**  * 人类  * @author   *  */ class Person implements Serializable {     private static final long serialVersionUID = -9102017020286042305L;       private String name;    // 姓名     private int age;        // 年龄     private Car car;        // 座驾       public Person(String name, int age, Car car) {         this.name = name;         this.age = age;         this.car = car;     }       public String getName() {         return name;     }       public void setName(String name) {         this.name = name;     }       public int getAge() {         return age;     }       public void setAge(int age) {         this.age = age;     }       public Car getCar() {         return car;     }       public void setCar(Car car) {         this.car = car;     }       @Override     public String toString() {         return "Person [name=" + name + ", age=" + age + ", car=" + car + "]";     }   }

 

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/**  * 小汽车类  * @author   *  */ class Car implements Serializable {     private static final long serialVersionUID = -5713945027627603702L;       private String brand;       // 品牌     private int maxSpeed;       // 最高时速       public Car(String brand, int maxSpeed) {         this.brand = brand;         this.maxSpeed = maxSpeed;     }       public String getBrand() {         return brand;     }       public void setBrand(String brand) {         this.brand = brand;     }       public int getMaxSpeed() {         return maxSpeed;     }       public void setMaxSpeed(int maxSpeed) {         this.maxSpeed = maxSpeed;     }       @Override     public String toString() {         return "Car [brand=" + brand + ", maxSpeed=" + maxSpeed + "]";     }   }

 

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class CloneTest {       public static void main(String[] args) {         try {             Person p1 = new Person("Hao LUO", 33, new Car("Benz", 300));             Person p2 = MyUtil.clone(p1);   // 深度克隆             p2.getCar().setBrand("BYD");             // 修改克隆的Person对象p2关联的汽车对象的品牌属性             // 原来的Person对象p1关联的汽车不会受到任何影响             // 因为在克隆Person对象时其关联的汽车对象也被克隆了             System.out.println(p1);         } catch (Exception e) {             e.printStackTrace();         }     } }