FileAlreadyExistsException with REPLACE_EXISTING option

Question

Inside my code there is a loop to substitute a file with another file.

This is done with:

java.nio.file.Files.move(Path source, Path target, CopyOption... options) throws IOException

The following exception is thrown:

Exception in thread "main" java.nio.file.FileAlreadyExistsException: C:\BRUTE-FORCE\Test-Loads-2-forces-only.dat.temp -> C:\BRUTE-FORCE\Test-Loads-2-forces-only.dat
    at sun.nio.fs.WindowsException.translateToIOException(Unknown Source)
    at sun.nio.fs.WindowsException.rethrowAsIOException(Unknown Source)
    at sun.nio.fs.WindowsFileCopy.move(Unknown Source)
    at sun.nio.fs.WindowsFileSystemProvider.move(Unknown Source)
    at java.nio.file.Files.move(Unknown Source)
(*) at bruteforce.Main.changeValue(Main.java:260)
    at bruteforce.Main.main(Main.java:71)

The line at which the exception is thrown:

(*) at bruteforce.Main.changeValue(Main.java:260):

Files.move(path, path.resolveSibling("DESTINY_FILE"), REPLACE_EXISTING);

Javadoc defines the exception:

...
FileAlreadyExistsException - if the target file exists but cannot be replaced because the REPLACE_EXISTING option is not specified (optional specific exception) 
...

The code clearly specifies REPLACE_EXISTING.

Also the option is imported at the beginning of the file:

import static java.nio.file.StandardCopyOption.REPLACE_EXISTING;

Any hint?

It could be due to the computer (or the HDD) hybernates or something similar? I have set the enegy options not suspends while using the power grid.

Thanks in advance

Answer 1

Files.move is not an atomic operation (unless of course ATOMIC_MOVE is specified), so what i assume is happenig some other IO got lock on this file.

Please make sure you:

• Lunch close() method on this resource or use try-with-resources

• Your OS is not using this file (eg. opened in Notepad, you lunch tail against it)

If you file is often accesed, then you can try to create loop that checks Files.isWritable()