Serializable and clone

      
// : appendixa:Compete.java
// From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002
// www.BruceEckel.com. See copyright notice in CopyRight.txt.

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

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.err.println("Thing3 can't clone");
    }
    return o;
  }
}

class Thing4 implements Cloneable {
  private Thing3 o3 = new Thing3();

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

public class Compete {
  public static final int SIZE = 25000;

  public static void main(String[] args) throws Exception {
    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();
    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");
  }
} ///:~

Related examples in the same category

1.	A Cloning Example
2.	Class is declared to be cloneable.
3.	Arrays are automatically cloneable
4.	Clone objects
5.	Creating a Deep Copy
6.	Shallow Copy Test
7.	Deep Copy Test
8.	Uses serialization to perform deep copy cloning.
9.	Tests cloning to see if destination of references are also cloned
10.	Creating local copies with clone
11.	You can insert Cloneability at any level of inheritance
12.	Cloning a composed object
13.	Go through a few gyrations to add cloning to your own class
14.	Checking to see if a reference can be cloned
15.	The clone operation works for only a few items in the standard Java library
16.	Demonstration of cloning
17.	Simple demo of avoiding side-effects by using Object.clone
18.	Clone an object with clone method from parent
19.	Manipulate properties after clone operation
20.	Deep clone Object
21.	Serializable Clone
22.	Utility for object cloning
23.	Clone Via Serialization
24.	Clone demo
25.	Deep clone serializing/de-serializng Clone
26.	Implements a pool of internalized objects
27.	A collection of utilities to workaround limitations of Java clone framework
28.	This program demonstrates cloning
29.	Returns a copy of the object, or null if the object cannot be serialized.
30.	Deep-copies the values from one object to the other
31.	Object Deep copy

Serializable and clone : Clone « Class « Java

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