To run your javaCup, in the directory that is one layer above java_cup, type
java java_cup.Main < yourCupFile
The above command will generate the parser. It needs to work together with a scanner.
You can also look at the bat files calc.bat and calc2.bat, to see the sequence of command to run the program. Note that JLex package should be also under your current directory. You can run those commands in sequence
automatically by typing "calc" in Windows.
In Unix/Linux/Ubunto/OS X, you can type "./calc.bat" to run the script. You may need to change the access mode by typing
chmod 755 calc.bat