Java.io.LineNumberReader.reset() Method

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Description

The java.io.LineNumberReader.reset() method reset the stream to the most recent mark.

Declaration

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

public void reset()

Parameters

NA

Return Value

The method does not return any value.

Exception

IOException − If the stream has not been marked, or if the mark has been invalidated.

Example

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

package com.tutorialspoint;

import java.io.FileReader;
import java.io.IOException;
import java.io.LineNumberReader;

public class LineNumberReaderDemo {
   public static void main(String[] args) throws IOException {
      FileReader fr = null;
      LineNumberReader lnr = null;
         
      try {
         // create new reader
         fr = new FileReader("C:/test.txt");
         lnr = new LineNumberReader(fr);
         
         // reads and prints data from reader
         System.out.println((char)lnr.read());
         System.out.println((char)lnr.read());
         
         // mark invoked at this position
         lnr.mark(0);
         System.out.println("mark() invoked");
         System.out.println((char)lnr.read());
         System.out.println((char)lnr.read());
         
         // if this reader supports mark() an reset()
         if(lnr.markSupported()) {
         
            // reset() repositioned the stream to the mark
            lnr.reset();
            System.out.println("reset() invoked");
            System.out.println((char)lnr.read());
            System.out.println((char)lnr.read());
         }
         
      } catch(Exception e) {
         // if any error occurs
         e.printStackTrace();
      } finally {
         // closes the stream and releases system resources
         if(fr!=null)
            fr.close();
         if(lnr!=null)
            lnr.close();
      }
   }
}

Assuming we have a text file c:/test.txt, which has the following content. This file will be used as an input for our example program −

ABCDE

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

A
B
mark() invoked
C
D
reset() invoked
C
D