Why is the first line of my file not being counted?

Question

I am trying to create a program that counts lines of code, where the commented lines are not included. I have come up with the code below, and its almost working completely, however when gets the strings from the file, it seems to be skipping the first line. Any help would be greatly appreciated!

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.*;

public class locCounter 
{

public locCounter(String filename) 
{
    System.out.println("Counting lines in " + filename + "...");
}

public static void main(String[] args)  throws FileNotFoundException
{
    boolean isEOF = false;

    System.out.println( "What file would you like to count the lines of code for?" );
    String programName = "test1.txt";
    //System.out.println(programName);

    locCounter countLines = new locCounter(programName);
    try ( BufferedReader reader = new BufferedReader( new FileReader( programName )))
    {
        String line = reader.readLine();
        int counter = 0;
        while ((line = reader.readLine()) != null)
        {
            line = line.trim();
            System.out.println(line);
            if (line.startsWith("//"))
            {
                counter = counter;
            }
            else
            {
                counter = counter + 1;
            }
        }
        System.out.println(counter);
        reader.close();
    }
    catch (FileNotFoundException ex)
    {
        System.out.println("The file was not found in the current directory.");
    }
    catch (IOException e)
    {
        System.exit(0);
    }

}
}

test1.txt

This file has one line of code
    // This comment should not count
        This file now has two lines of code
    // Another comment that shouldn't be counted
}
A total of 4 lines should be counted.

Output

What file would you like to count the lines of code for?
Counting lines in test1.txt...
// This comment should not count
This file now has two lines of code
// Another comment that shouldn't be counted
}
A total of 4 lines should be counted.
3

admix · Accepted Answer · 2016-01-31T02:11:44.687

2

Remove this line from your code:

String line = reader.readLine();

It basically reads the line. And later on you have 'while ((line = reader.readLine()) != null)' inside the while condition again, so you read 2 lines in total, but only start processing from second line.

edited Jan 31 '16 at 02:11

answered Jan 31 '16 at 02:00

admix

1,752
3
22
27

Thank you! Sill mistake leaving some code behind from another route I was testing. – Casey Jan 31 '16 at 02:23

score 2 · Answer 2 · answered Jan 31 '16 at 02:31

AS @admix has said, your problem is that you should replace this line of code

String line = reader.readLine();

with

String line;

By now, your problem has been solved. As I can see you use JDK7, so you can write your read file code with fewer lines.

    Path path = Paths.get(programName);
    try {
        try (BufferedReader reader = Files.newBufferedReader(path)){
            String line;
            while ((line = reader.readLine()) != null) {
                //process each line in some way
            }
        }
    } catch (IOException e) {
        e.printStackTrace();
    }

or even cleaner version

    Path path = Paths.get(programName);
    try {
        List<String> lines = Files.readAllLines(path);
        for (String line : lines) {
            //process each line in some way
        }
    } catch (IOException e) {
        e.printStackTrace();
    }

In addition, your program will be more elegant is you remove those lines, which is unnecessary.

       if (line.startsWith("//"))
        {
            counter = counter;
        }

Thanks! Appreciate the advice. – Casey Jan 31 '16 at 21:55 — Casey, Jan 31 '16 at 21:55

Why is the first line of my file not being counted?

2 Answers2