How to make TrueZip overwrite a temporary file?

Question

I want to create a temporary file as a ZIP archive. The first step is basically

File.createTempFile ("xxx", ".zip", null);

However, now I cannot get TrueZip add anything to this "archive" -- it obviously isn't an archive yet, it is a zero-byte placeholder file. However, the library doesn't recognize it, tries to read the file and bumps into EOF, of course:

Exception in thread "main" java.io.EOFException
         at de.schlichtherle.truezip.rof.AbstractReadOnlyFile.readFully(AbstractReadOnlyFile.java:37)
         ...

I tried to call TFile.mkdir() on it first, but this gives the same exception as TFile.cp*(), i.e. TrueZip still doesn't want to overwrite the file.

I can of course delete the file first, but that's not quite a proper solution, because it creates a race condition.