Java.io.ObjectOutputStream.reset() Method

---

---

Description

The java.io.ObjectOutputStream.reset() method will disregard the state of any objects already written to the stream. The state is reset to be the same as a new ObjectOutputStream. The current point in the stream is marked as reset so the corresponding ObjectInputStream will be reset at the same point. Objects previously written to the stream will not be referred to as already being in the stream. They will be written to the stream again.

Declaration

Following is the declaration for java.io.ObjectOutputStream.reset() method.

public void reset()

Parameters

obj − The object to be replaced.

Return Value

This method does not return a value.

Exception

IOException − If reset() is invoked while serializing an object.

Example

The following example shows the usage of java.io.ObjectOutputStream.reset() method.

package com.tutorialspoint;

import java.io.*;

public class ObjectOutputStreamDemo {
   public static void main(String[] args) {
      Object s = "Hello World!";
      Object s2 = "Bye World!";
      
      try {
         // create a new file with an ObjectOutputStream
         FileOutputStream out = new FileOutputStream("test.txt");
         ObjectOutputStream oout = new ObjectOutputStream(out);

         // write something in the file
         oout.writeObject(s);

         // reset the stream and rewrite what is already written
         oout.reset();

         // write something again
         oout.writeObject(s2);

         // close the stream
         oout.close();

         // create an ObjectInputStream for the file we created before
         ObjectInputStream ois = new ObjectInputStream(new FileInputStream("test.txt"));

         // read and print a string
         System.out.println("" + (String) ois.readObject());
         System.out.println("" + (String) ois.readObject());
      } catch (Exception ex) {
         ex.printStackTrace();
      }
   }
}

Let us compile and run the above program, this will produce the following result −

Hello World!
Bye World!