Find the total number of lines (sum) in all files in a directory

[Rithanya Laxmi]

Hi,


How to find the total number of lines in all files in a directory in java? I have written the below code which fetches number of lines of each files, where I need to find total number of lines in all files in "Test" directory. How to refactor the code get the total number of lines in all files in a directory ?

                private static final String FILE_DIRECTORY = "D:/Test/";
	private static String COUNT_JAVA_FILE = ".java";

	public static void main(String[] args) throws FileNotFoundException {
		Map<String, Integer> result = new HashMap<String, Integer>();
		File directory = new File(FILE_DIRECTORY);
		File[] files = directory.listFiles();
		System.out.println("The number of files:"+files.length);
		for (File file : files) {
			if (file.isFile() && file.getName().contains(COUNT_JAVA_FILE)) {
				Scanner scanner = new Scanner(new FileReader(file));
				int lineCount = 0;
				try {
					for (lineCount = 0; scanner.nextLine() != null; lineCount++);
				} catch (NoSuchElementException e) {
					result.put(file.getName(), lineCount);
				}
			}
		}
		System.out.println(result);
	}

Please clarify.

Thanks.

[Winston Gutkowski]

Rithanya Laxmi wrote:How to find the total number of lines in all files in a directory in java? I have written the below code which fetches number of lines of each files, where I need to find total number of lines in all files in "Test" directory. How to refactor the code get the total number of lines in all files in a directory ?

Answer: Not easily, because not all files have lines (eg, a JPEG file); and there is no fullproof method for working out what type of file you have. If you are happy to assume that all .java files are OK, then you might want to look at LineNumberReader.

However, my advice: Get it right for ONE file; then start worrying about directories.

Winston

[Rithanya Laxmi]

Thanks. I able to get the total lines of individual files , as shown in the code, but now i need to get the sum of total lines of all the files in the "Test" directory. Please provide your input.

[fred rosenberger]

My advice:

StopCoding. You're trying to write the code before you've thought through the problem.

You want to separate out the discrete components of your problem into their own methods. Some of the things your program should be able to do:

1) Given a file name, a method that can return the number of lines in the file
2) Given a directory, generate a list of files contained in that directory
3) Given a list of files, iterate through it, looking at each file name one at a time.
4) keep a running sum of a bunch of numbers, being given them one at a time.

I think that once you figure out how to do each of the above, and then start wiring them together, you'll find a) a few more tasks/methods that need to be written, and b) you'll end up with a working program that is readable and debuggable.