Some applications must keep small amounts of information between thetimes they are run. For example a personal calendar or personalinformation system, will store information after each session. Insteadof using a Random access file or even a database to store thisinformation, use Java Object Serialization. Object serialization is fastand reliable, and it restores the complete state of all of your objects.To use Object Serialization, use the following code (JDK 1.1):

 FileOutputStream   fos = new FileOutputStream("c:\store\objects.ser");ObjectOutputStream oos = new ObjectOutputStream( fos );// Write out the root Object of your in-memory object structure.// Object Serialization will write out all of the objects to the diskfile.fos.writeObject( rootObject );

To read them back in, reverse the process with:

 FileInputStream fis = new FileInputStream( "c:\store\object.ser");ObjectInputStream oos = new ObjectInputStream( fis );Object root = oos.readObject();

You must remember to “implement” the interface java.io.Serializable inall of the classes that are to be written to disk:

 public class Person implements java.io.Serializable{   . . .}

This technique works when you want to save the entire state of yourmemory to disk at one time. If you need to store single objects, thenyou will need a different architecture.