file.delete() returns false even though file.exists(), file.canRead(), file.canWrite(), file.canExecute() all return true

Solution 1:

Another bug in Java. I seldom find them, only my second in my 10 year career. This is my solution, as others have mentioned. I have nether used System.gc(). But here, in my case, it is absolutely crucial. Weird? YES!

finally
{
    try
    {
        in.close();
        in = null;
        out.flush();
        out.close();
        out = null;
        System.gc();
    }
    catch (IOException e)
    {
        logger.error(e.getMessage());
        e.printStackTrace();
    }
}

Solution 2:

It was pretty odd the trick that worked. The thing is when I have previously read the content of the file, I used BufferedReader. After reading, I closed the buffer.

Meanwhile I switched and now I'm reading the content using FileInputStream. Also after finishing reading I close the stream. And now it's working.

The problem is I don't have the explanation for this.

I don't know BufferedReader and FileOutputStream to be incompatible.

Solution 3:

I tried this simple thing and it seems to be working.

file.setWritable(true);
file.delete();

It works for me.

If this does not work try to run your Java application with sudo if on linux and as administrator when on windows. Just to make sure Java has rights to change the file properties.