AW: Learning Jackrabbit - Extracted files are length zero

[Cech. Ulrich]

< resNode.setProperty("jcr:data", new FileInputStream(file));>

I think, the problem lies here in the importFile() method:
Try out this one:
resNode.setProperty(JcrConstants.JCR_DATA, 
resNode.getSession().getValueFactory().createBinary(input));

important: "input" is an InputStream to the file, you want to import