Question

I’m writing a test for a piece of code that has an IOException catch in it that I’m trying to cover. The try/catch looks something like this:

try {     oos = new ObjectOutputStream(new FileOutputStream(cacheFileName)); } catch (IOException e) {     LOGGER.error('Bad news!', e); } finally { 

The easiest way seems to make FileOutputStream throw a FileNotFoundException, but perhaps I’m going about this all the wrong way.

Anyone out there have any tips?

Answer 1

From your comment:

Yes, I suppose the question should really have been ‘How do I create a file that does not exist on both Linux and Windows?’ On windows, I can use ‘new File(‘X:/’)’, where X: is a drive letter that does not exist. On Linux, this does not work because that is a valid file name.

Look at java.io.File.createTempFile. Use it to create the file and then delete it.

Probably pass it something like:

File tempFile;  tempFile = createTempFile(getClass().getName(),                            Long.toString(System.currentTimeMillis()); tempFile.delete(); 

That should give you a unique name in a platform indendent manner that you can safely use without (much) fear of it existing.