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Java LineNumberReader reset() Method with Example

LineNumberReader Class reset() method: Here, we are going to learn about the reset() method of LineNumberReader Class with its syntax and example.
Submitted by Preeti Jain, on April 16, 2020

LineNumberReader Class reset() method

• reset() method is available in java.io package.
• reset() method is used to reset this LineNumberReader stream to the position of the most recent mark was set by calling its mark() method.
• reset() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.
• reset() method may throw an exception at the time of resetting the stream.
  IOException: This exception may throw when this stream has not been marked or set mark is invalid.

Syntax:

    public void reset();

Parameter(s):

• It does not accept any parameter.

Return value:

The return type of the method is void, it returns nothing.

Example:

// Java program to demonstrate the example 
// of void reset() method of LineNumberReader

import java.io.*;

public class ResetOfLNR {
 public static void main(String[] args) throws Exception {
  FileReader fr_stm = null;
  LineNumberReader line_r = null;
  int val = 0;

  try {
   // Instantiates FileReader and LineNumberReader
   fr_stm = new FileReader("D:\\includehelp.txt");
   line_r = new LineNumberReader(fr_stm);

   // By using read() method isto 
   // read the character from line_r
   char ch1 = (char) line_r.read();
   char ch2 = (char) line_r.read();
   char ch3 = (char) line_r.read();

   System.out.println("ch1: " + ch1);
   System.out.println("ch2: " + ch2);
   System.out.println("ch3: " + ch3);

   // By using mark() method isto
   // set the current position in this
   // line_r

   System.out.println("line_r.mark(0): ");
   line_r.mark(0);
   char ch4 = (char) line_r.read();
   char ch5 = (char) line_r.read();

   System.out.println("ch4: " + ch4);
   System.out.println("ch5: " + ch5);

   // By using reset() method isto
   // reset the stream to the position 
   // set by the call mark() method

   System.out.println("line_r.reset(): ");
   line_r.reset();
   char ch6 = (char) line_r.read();
   char ch7 = (char) line_r.read();
   char ch8 = (char) line_r.read();
   char ch9 = (char) line_r.read();
   char ch10 = (char) line_r.read();
   char ch11 = (char) line_r.read();


   System.out.println("ch4: " + ch6);
   System.out.println("ch5: " + ch7);
   System.out.println("ch6: " + ch8);
   System.out.println("ch7: " + ch9);
   System.out.println("ch8: " + ch10);
   System.out.println("ch9: " + ch11);

  } catch (Exception ex) {
   System.out.println(ex.toString());
  } finally {
   // with the help of this block is to
   // free all necessary resources linked
   // with the stream
   if (fr_stm != null) {
    fr_stm.close();
    if (line_r != null) {
     line_r.close();
    }
   }
  }
 }
}

Output

ch1: J
ch2: A
ch3: V
line_r.mark(0):
ch4: A
ch5: W
line_r.reset():
ch4: A
ch5: W
ch6: O
ch7: R
ch8: L
ch9: D