PushbackInputStream reset() method in Java with Examples

Last Updated : 22 Sep, 2022

The reset() method of PushbackInputStream class in Java is used to reset the steam to the position where mark() method was called. This method does nothing for PushbackInputStream. Syntax:

public void reset()
           throws IOException

Overrides: This method overrides the reset() method of FilterInputStream class. Parameters: This method does not accept any parameter. Return value: This method does not return any value. Exceptions: This method throws IOException whenever this method is called. Below programs illustrate reset() method of PushbackInputStream class in IO package: Program 1:

Java

// Java program to illustrate
// PushbackInputStream reset() method

import java.io.*;

public class GFG {
    public static void main(String[] args)
        throws IOException
    {

        // Create an array
        byte[] byteArray
            = new byte[] { 'G', 'E', 'E',
                           'K', 'S' };

        // Create inputStream
        InputStream inputStr
            = new ByteArrayInputStream(byteArray);

        // Create object of
        // PushbackInputStream
        PushbackInputStream pushbackInputStr
            = new PushbackInputStream(inputStr);

        for (int i = 0; i < byteArray.length; i++) {
            // Read the character
            System.out.print(
                (char)pushbackInputStr.read());
        }

        // Revoke reset() but it does nothing
        pushbackInputStr.reset();
    }
}

Output:

Exception in thread "main" java.io.IOException: mark/reset not supported GEEKS

Program 2:

Java

// Java program to illustrate
// PushbackInputStream reset() method

import java.io.*;

public class GFG {
    public static void main(String[] args)
        throws IOException
    {

        // Create an array
        byte[] byteArray
            = new byte[] { 'H', 'E', 'L',
                           'L', 'O' };

        // Create inputStream
        InputStream inputStr
            = new ByteArrayInputStream(byteArray);

        // Create object of
        // PushbackInputStream
        PushbackInputStream pushbackInputStr
            = new PushbackInputStream(inputStr);

        // Revoke reset()
        pushbackInputStr.reset();

        for (int i = 0; i < byteArray.length; i++) {
            // Read the character
            System.out.print(
                (char)pushbackInputStr.read());
        }
    }
}