Java Program to mark the current position in this input stream

The method java.io.InputStream.mark() is used to mark the current position in this input stream. This method requires a single parameter i.e. the bytes that can be read before the position marked is invalidated.

A program that demonstrates this is given as follows −

Example

import java.io.FileInputStream;
import java.io.InputStream;
public class Demo {
   public static void main(String[] args) throws Exception {
      InputStream i = null;
      try {
         i = new FileInputStream("C://JavaProgram//data.txt");
         System.out.println("Char : "+(char)i.read());
         System.out.println("Char : "+(char)i.read());
         System.out.println("Char : "+(char)i.read());
         i.mark(0);
         System.out.println("Char : "+(char)i.read());
         System.out.println("Char : "+(char)i.read());
         if(i.markSupported()){
            i.reset();
            System.out.println("Char : "+(char)i.read());
            System.out.println("Char : "+(char)i.read());
         }
      } catch(Exception e) {
         e.printStackTrace();
      }
   }
}

The output of the above program is as follows −

Output

Char : D
Char : A
Char : T
Char : A