That error you give is the first line of the stack trace that gets printed. One of the next few lines will show you the exact line number where the error occurs in your program. If that's not a help to you, it would certainly be to us -- so please let us know exactly which line in your program is causing this error.
That file.list() call is going to return the names of the files in that directory, but unless that directory is the current directory, the ZipFile constructor won't be able to find them. Instead of using list() use listFiles(), which returns File object instead of Strings, and pass aFile.getAbsolutePath() to Unzipme() (or change Unzipme() to take a File argument, and just pass the File.)