CODEWITHSUNDEEP
javaarrayssearchfilterfilenames
Jaskal
Jaskal

Reputation: 37

File Name checking

I was making a class that searches for missing files out of a sequence of them (IE: test-1.txt test-2.txt test-4.txt) out of curiosity and when I finally got it to work and I realized I had no idea how to keep checking for missing files after it finds one missing. The problem is that the counter I use to ask for what number in the sequence of files wont work after it finds a missing file because it's permanently off at that point. What I thought might work would be asking what is on the end of the current aFile.getName() and assigning it as an int to i regardless of the fact that it might not be a number(what goes into the actual counter that is a string and is put onto what is checked for). Appearently that doesn't work and gives me:

Exception in thread "main" java.lang.NumberFormatException: For input string: "t"
	at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
	at java.lang.Integer.parseInt(Integer.java:580)
	at java.lang.Integer.parseInt(Integer.java:615)
	at TestingClass5.main(TestingClass5.java:43)

Here's what I've got so far:

import java.io.File;
import java.io.FileFilter;
import java.io.FilenameFilter;
import javax.swing.JOptionPane;
public class TestFileSequence {
	public static void main(String[] args) {
		int i = 0;
		//Start Dialogue
		String userDefinedFilePath = JOptionPane.showInputDialog("Please input directory"); //File dir
		String userDefinedFileName = JOptionPane.showInputDialog("Please input file name"); //File extension
		String userDefinedFileType = JOptionPane.showInputDialog("Please input group extension"); //File name
		//Start Filter
		FilenameFilter userDefinedFilter = new FilenameFilter() {
			public boolean accept(File file, String name) {
				if (name.endsWith(userDefinedFileType)) {
					return true;
				} else {
					return false;
				}
			}
		};
		//Start Array
		File dir = new File(userDefinedFilePath);
		File[] files = dir.listFiles(userDefinedFilter);
		//Check for files matching description
		if (files.length == 0) {
			System.out.println("The directory doesn't contains any matching files. Please check the directory, extension, and name specified below for accuracy.");
			System.out.println("Directory Specified: " + userDefinedFilePath);
			System.out.println("Extension Specified: " + userDefinedFileType);
			System.out.println("Group Name Specified: " + userDefinedFileName);
		} else {
			//Check files for gaps in sequence
			for (File aFile: files) {
				String counter = Integer.toString(i);
				String check = userDefinedFileName + "-" + counter + userDefinedFileType;
				if (aFile.getName().equals(check)) {
					System.out.println("File: " + aFile.getName() + " is present.");
					i++;
				} else {
					System.out.println("Checked for :" + check);
					System.out.println("What was found: " + aFile.getName());
					String resetCounter = aFile.getName().substring(aFile.getName().length() - 1); //Assigns string resetCounter to the last character in the current aFile.getName() regardless if it isn't a number 
					int resetLength = Integer.parseInt(resetCounter);
					i = resetLength;
				}
			}
		}
	}
}

Upvotes: 0

Views: 172

Answers (1)

Peter Lawrey
Peter Lawrey

Reputation: 533492

You are trying to get the number at the end of the file name

String resetCounter = aFile.getName().substring(aFile.getName().length() - 1); 
//Assigns string resetCounter to the last character in the current aFile.getName() regardless if it isn't a number

for a file called test-1.txt so the last letter is t not 1

You could get the digit before the last . or after the first one or find any number in the file name instead. I suspect you want the number e.g. test-10.txt should be 10 not 0

You could do

String resetCounter = aFile.getName().replaceAll("[^0-9]+", "");

This just keeps the digits.

Upvotes: 1

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