Expression file.exists() returns true, reading file fails with FileNotFoundException

Question

Method returns FileNotFoundException:

String statSource = 'some path';
 try {

         File file = new File(statSource);

         if (!file.exists())
         {
             System.out.println(file.getPath() + " doesn't exist!");
         }
         else
         {
             System.out.println("OK!");
         }


         // otevření CSV
         csv = new CsvReader(statSource, ';', Charset.forName("windows-1250"));
     }

At first I get 'OK!' message, but on the last line I get FileNotFoundException. File is located on a local hard drive.

DO you have any idea what's wrong?

Answer 1

Assuming you are talking about this class, and that you are using JDK 7, do yourself a favour and use this:

final Path csvpath = Paths.get(statSource);

try (
    final InputStream in = Files.newInputStream(csvpath);
    final CsvReader csv = new CsvReader(in, ';', Charset.forName("windows-1250");
) {
    // operate on csv
}

If the file does not exist or whatever, you will at least get a meaningful exception: AccessDeniedException, NoSuchFileException, etc; all of them inheriting FileSystemException.

Answer 2

I think you are just giving the File name to the csvReader. for reading the Files in java, you have to use, FileReader.

Can you try changing the last line to,

csv = new CsvReader(new FileReader(statSource), ';', Charset.forName("windows-1250"));

Answer 3

FileNotFoundException - If the given file object does not denote an existing, writable regular file and a new regular file of that name cannot be created, or if some other error occurs while opening or creating the file

So a FileNotFoundException may be thrown in the following 3 cases.

1. File does not exist.
2. File is actually a directory.
3. The named file cannot be opened for reading for some reason, say permission

So, make sure you are operating on a file not a directory, and then try using file.canRead()(not reliable enough at windows though, see bug) to test it for the #3.