Question:
How can I convert a class instance to a byte array and thensubsequently reconstruct the original class from the byte array?

Answer:
Java’s Object Serialization API allows you to write class instancesto streams. In order to store a class instance in a byte arrayyou can wrap a ByteArrayOutputStream with an ObjectOutputStream.

To read a class instance from a byte array you can wrap anObjectInputStream with a ByteArrayInputStream. You justhave to remember that all serializable objects must implementthe Serializable interface. The following example demonstrateshow to do this.

import java.io.*;public class ByteSerialize {  public static void main(String[] args) {    Integer write, read;    ObjectOutputStream out;    ObjectInputStream in;    ByteArrayOutputStream byteStream;    byte[] bytes;    write = new Integer(5);    System.out.println("write: " + write);    try {      byteStream = new ByteArrayOutputStream();      out = new ObjectOutputStream(byteStream);      out.writeObject(write);      out.close();      // Byte representation of integer      bytes = byteStream.toByteArray();      in = new ObjectInputStream(new ByteArrayInputStream(bytes));      read = (Integer)in.readObject();      in.close();    } catch(IOException ioe) {      ioe.printStackTrace();      return;    } catch(ClassNotFoundException cnfe) {      cnfe.printStackTrace();      return;    } catch(ClassCastException cce) {      cce.printStackTrace();      return;    }    System.out.println("read : " + read);  }}