Why can't Java create this file on my Ubuntu desktop?

Question

I have the following existing directory structure on my file system (Ubuntu 12.04 desktop using ext4):

/
    home/
        myuser/
            .myapp/
                logs/
                    myapp.log
                data/
                lib/

...and the following Java code:

try {
    // If no such file exists, create it and write zero (0) to it.
    if(!myFile.exists()) {
        System.out.println("myFile is: " + myFile.getAbsolutePath());
        myFile.createNewFile();
        myFileWriter.write("0"); // Configured to write to myFile
    }
} catch(IOException ioExc) {
    logger.error(ExceptionUtils.getStackTrace(ioExc));
    throw new RuntimeException(ioExc);
}

...that is throwing the following exception:

myFile is: /home/myuser/.myapp/data/replay/Loader-0-replay.log
java.lang.RuntimeException: java.io.IOException: No such file or directory
    at net.myuser.myapp.tools.myapp.Loader.<init>(Loader.java:69)
    at net.myuser.myapp.tools.myapp.MyAppTool.loadWords(MyAppTool.java:125)
    at net.myuser.myapp.tools.myapp.MyAppTool.run(MyAppTool.java:65)
    at net.myuser.myapp.tools.myapp.MyAppTool.main(MyAppTool.java:41)
Caused by: java.io.IOException: No such file or directory
    at java.io.UnixFileSystem.createFileExclusively(Native Method)
    at java.io.File.createNewFile(File.java:900)
    at net.myuser.myapp.tools.myapp.Loader.<init>(Loader.java:62)
    ... 3 more

What is going on here? It says "No such file or directory", but isn't that what createNewFile() is supposed to do for me? Thanks in advance!

Answer 1

You need to create the folder /home/myuser/.myapp/data/replay before you create the file.

You could try something like

if (!myFile.exists()) {
    System.out.println("myFile is: " + myFile.getAbsolutePath());
    if (!myFile.getParentFile().exists()) {
        myFile.getParentFile().mkdirs();
    }
    myFile.createNewFile();
    myFileWriter.write("0"); // Configured to write to myFile
}

Check the reference:

• File.mkdir()
• File.mkdirs()

Answer 2

/home/myuser/.myapp/data/replay/Loader-0-replay.log

I don't see 'replay' in the directory listing you gave.

Try getting the parent File from myFile and then calling File.mkdirs().

Answer 3

try following code:

try {
    // If no such file exists, create it and write zero (0) to it.
    if(!myFile.exists()) {
        System.out.println("myFile is: " + myFile.getAbsolutePath());
        if(!myFile.getParentFile().exists())myFile.getParentFile().mkdirs();
        myFile.createNewFile();
        myFileWriter.write("0"); // Configured to write to myFile
    }
} catch(IOException ioExc) {
    logger.error(ExceptionUtils.getStackTrace(ioExc));
    throw new RuntimeException(ioExc);
}