Storing Objects in a File : Object Serialization « File « Java Tutorial

1. Java Tutorial
2. File
3. Object Serialization

import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

public class MainClass {
  public static void main(String[] args) throws Exception {
    Junk obj1 = new Junk("A");
    Junk obj2 = new Junk("B");
    Junk obj3 = new Junk("V");
    ObjectOutputStream objectOut = new ObjectOutputStream(new BufferedOutputStream(
        new FileOutputStream("C:/JunkObjects.bin")));

    objectOut.writeObject(obj1); // Write object
    objectOut.writeObject(obj2); // Write object
    objectOut.writeObject(obj3); // Write object
    System.out.println("\n\nobj1:\n" + obj1 + "\n\nobj2:\n" + obj2 + "\n\nobj3:\n" + obj3);
    objectOut.close(); // Close the output stream

  }
}

class Junk implements Serializable{
  String str;

  public Junk(String s) {
    str = s;
  }

}

obj1:
Junk@c2a132

obj2:
Junk@337d0f

obj3:
Junk@1e4cbc4