How to get the total number of lines of a file in Java
Published: June 1, 2010 , Updated: May 30, 2010 , Author: mkyong
The LineNumberReader class is a useful class to handle the lines of a file, you can loop the LineNumberReader.readLine() method and accumulate it as the total number of lines. A line is considered a line if it ends with a line feed (‘\n’) or a carriage return (‘\r’).
Example
A text file named “c:\\ihave10lines.txt”, contains 10 lines
Line 1 Line 2 Line 3 Line 4 Line 5 Line 6 Line 7 Line 8 Line 9 Line 10
Counts the line
package com.mkyong.file; import java.io.File; import java.io.FileReader; import java.io.IOException; import java.io.LineNumberReader; public class LineNumberReaderExample { public static void main(String[] args) { try{ File file =new File("c:\\ihave10lines.txt"); if(file.exists()){ FileReader fr = new FileReader(file); LineNumberReader lnr = new LineNumberReader(fr); int linenumber = 0; while (lnr.readLine() != null){ linenumber++; } System.out.println("Total number of lines : " + linenumber); lnr.close(); }else{ System.out.println("File does not exists!"); } }catch(IOException e){ e.printStackTrace(); } } }
Result
Total number of lines : 10
Open text file. Click on Edit>Go To. Give a huge number than expected number of lines. say if you expect to have 2000 lines, give 5000 or just give 200000. It gives an error “The Line number is beyond the total number of lines” and shows up the the immediately available line. If you have 2379 lines it gives 2380. So whatever it shows up minus 1 is the actual number of lines in the text file. Cheers!!
It was very helpful. thanks a lot