Serialization

jedistar -

As to what it can be used for, I should elaborate.  Two popular uses of serialization are:

- Enabling RMI - this is how objects are sent from a local VM to the remote VM

- One way to store information (properties/settings, etc) for an application to disk (instead of creating a text-based format, simply write your setting objects straight to a file and read them in as simply)

Also, here are some more examples straight from Sun:
http://java.sun.com/j2se/1.5.0/docs/guide/serialization/examples/index.html

Cheers,
Astopheles

From JDK 1.4 you can serialize in XML also:


import java.util.Vector;
import java.beans.XMLEncoder;
import java.io.ByteArrayOutputStream;

public class Dummy {
    public static void main(String[] args)
    {
        final Vector toSerialize = new Vector();
        toSerialize.add("This is string");
        toSerialize.add(new Integer(1));
        toSerialize.add(new Long(1));
        toSerialize.add(new Double(1));

        final ByteArrayOutputStream out = new ByteArrayOutputStream();
        XMLEncoder encoder = new XMLEncoder(out);
        encoder.writeObject(toSerialize);
        encoder.flush();

        System.out.println("out:\n"+out.toString());

    }
}


produces:
out:
<?xml version="1.0" encoding="UTF-8"?>
<java version="1.4.2_06" class="java.beans.XMLDecoder">
 <object class="java.util.Vector">
  <void method="add">
   <string>This is string</string>
  </void>
  <void method="add">
   <int>1</int>
  </void>
  <void method="add">
   <long>1</long>
  </void>
  <void method="add">
   <double>1.0</double>
  </void>
 </object>

FileOutputStream fileOut = new FileOutputStream("MyFile.ser");
ObjectOutputStream out = new ObjectOutputStream(fileOut);
out.writeObject(objectToBeSerialized);
out.close();
fileOut.close();