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，经过对象的序列化和反序列化实现克隆，能够实现真正的深度克隆，代码以下。

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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可以释放资源，这一点不一样于对外部资源（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              // 由于在克隆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();          }      } }