Since you're unable to assign a list to the aliases, I'm doing a get and addAll(..) but this fails since getAliases() returns null.

My code:

Collection<String> aliases = ...

GridFSInputFile inputFile = gridFS.createFile(file);
inputFile.setContentType(contentType);
inputFile.setFilename(filename);
inputFile.getAliases().addAll(aliases);
inputFile.save();