This is a small utility I wrote semi-seriously to generate cool usernames by reading a file containing the words and finding all the possible combinations of two words. It's written in C++, which I'm less skilled at than Java, but it works.
Download the exe in the releases section. Execute it. It will ask you to point to a valid text file to take as input, and then to the number of maximum character permitted in permutations. If all is valid, it will be generated in the working directory, which will follow be named according to the current nanoseconds since epoch, followed by the name of the original file and "__output.txt". See names.txt for an example of a valid input file, and names_output.txt to see the result of an execution.
A Windows machine.