Why won't this code display Error: Could not find file when e is thrown by a nonexistant file?

Question

Here is my code. The FileNotFoundException is not being thrown for some reason when i give it a fileName that does not exist.

 public static String Question1( String fileName )
 {   
    String message = ""; 
    if ( fileName == null )
    {   
        fileName = "files/question1/sample.txt"; 
    }

    try
    {  

        Scanner fileScan = new Scanner( new File ( fileName ));

        while ( fileScan.hasNext() )
        {
            String readLine = fileScan.nextLine();

            if ( message.equals( "" ) )
            {
                message = readLine + "\n";
            }
            else
            {
                message = message + readLine + "\n";
            }
        }
    }

    catch ( FileNotFoundException e )
    {
        message = "Error: Could not find file!";
    }

    return message;
 }

When i run the code with a fileName that does not exist, the message returned is "" instead of "Error: Could not find file!"

Have you debugged the code and are you sure the exception is caught? — Dion V., Dec 15 '14 at 07:20

paxdiablo · Accepted Answer · 2014-12-15T07:33:09.293

I call shenanigans :-) I suspect the file does exist in your case since this code works just fine:

import java.io.FileNotFoundException;
import java.util.Scanner;
import java.io.File;

public class Test {
    public static String Question1(String fileName) {   
        String message = "";
        if ( fileName == null )
            fileName = "files/question1/sample.txt"; 

        try {  
            Scanner fileScan = new Scanner(new File(fileName));
            while (fileScan.hasNext()) {
                String readLine = fileScan.nextLine();
                if (message.equals("")) {
                    message = readLine + "\n";
                } else {
                    message = message + readLine + "\n";
                }
            }
        } catch (FileNotFoundException e) {
            message = "Error: Could not find file!";
        }

        return message;
    }

    public static void main(String[] args) {
        System.out.println(Question1("no_such_file.txt"));
    }
}

Running that outputs, as expected:

Error: Could not find file!

When I create that file, the program outputs its contents.

I suggest going back to look at your file system again, then run your code through a single-stepping debugger to track the code flow.

You're right. I changed the file name in the unit test from blah.txt to blahlsdfjs.txt and now its working fine. Thanks. — CrypticLightning, Dec 15 '14 at 07:33

score 0 · Answer 2 · answered Dec 15 '14 at 07:42

0

Are you sure the exception FileNotFoundException is thrown?

What could be happening is at the relative path of where this class is placed ,the file that you think is not present,could be present.

answered Dec 15 '14 at 07:42

abhati

309
1
6

Why won't this code display Error: Could not find file when e is thrown by a nonexistant file?

2 Answers2