A DESCRIPTION OF THE PROBLEM :
The documentation says: "By default, line numbering begins at 0." However it starts at 1.

I wrote a little test routine to prove it to myself:

import java.io.*;

public class test {

    public static void main(String [] args) {
        try {
            LineNumberReader lr = new LineNumberReader(new FileReader("/some/file/here.txt"));
            String currentLine = null;
            int currLine = -1;
            
            while ((currentLine = lr.readLine()) != null) {
                currLine = lr.getLineNumber();
                System.out.println("line nber " + currLine + " : " + currentLine);
            }
            lr.close();
        } catch (IOException e) {
            System.err.println("Error: " + e);
        }
        
    }

}

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
By default, line numbering begins at 1.
ACTUAL -
By default, line numbering begins at 0.

URL OF FAULTY DOCUMENTATION :
http://java.sun.com/j2se/1.4.2/docs/api/java/io/LineNumberReader.html