通过序列化举行深层复制(java)[Java编程]

//: Compete.java
import java.io.*;

class Thing1 implements Serializable {}
class Thing2 implements Serializable {
  Thing1 o1 = new Thing1();
}

class Thing3 implements Cloneable {
  public Object clone() {
    Object o = null;
    try {
      o = super.clone();
    } catch (CloneNotSupportedException e) {
      System.out.println("Thing3 can't clone");
    }
    return o;
  }
}

class Thing4 implements Cloneable {
  Thing3 o3 = new Thing3();
  public Object clone() {
    Thing4 o = null;
    try {
      o = (Thing4)super.clone();
    } catch (CloneNotSupportedException e) {
      System.out.println("Thing4 can't clone");
    }
    // Clone the field, too:
    o.o3 = (Thing3)o3.clone();
    return o;
  }
}

public class Compete {
  static final int SIZE = 5000;
  public static void main(String[] args) {
    Thing2[] a = new Thing2[SIZE];
    for(int i = 0; i < a.length; i++)
      a[i] = new Thing2();
    Thing4[] b = new Thing4[SIZE];
    for(int i = 0; i < b.length; i++)
      b[i] = new Thing4();
    try {
      long t1 = System.currentTimeMillis();
      ByteArrayOutputStream buf = 
        new ByteArrayOutputStream();
      ObjectOutputStream o =
        new ObjectOutputStream(buf);
      for(int i = 0; i < a.length; i++)
        o.writeObject(a[i]);
      // Now get copies:
      ObjectInputStream in =
        new ObjectInputStream(
          new ByteArrayInputStream(
            buf.toByteArray()));
      Thing2[] c = new Thing2[SIZE];
      for(int i = 0; i < c.length; i++)
        c[i] = (Thing2)in.readObject();
      long t2 = System.currentTimeMillis();
      System.out.println(
        "Duplication via serialization: " +
        (t2 - t1) + " Milliseconds");
      // Now try cloning:
      t1 = System.currentTimeMillis();
      Thing4[] d = new Thing4[SIZE];
      for(int i = 0; i < d.length; i++)
        d[i] = (Thing4)b[i].clone();
      t2 = System.currentTimeMillis();
      System.out.println(
        "Duplication via cloning: " +
        (t2 - t1) + " Milliseconds");
    } catch(Exception e) {
      e.printStackTrace();
    }
  }
} ///:~

Duplication via serialization: 3400 Milliseconds
Duplication via cloning: 110 Milliseconds

Duplication via serialization: 3410 Milliseconds
Duplication via cloning: 110 Milliseconds

Duplication via serialization: 3520 Milliseconds
Duplication via cloning: 110 Milliseconds