The code below will process the String array that contains the command line arguments passed to the main method when Java runs.
A google search will show you how to turn on and provide command line args to your Java program in Eclipse, etc.
class MainArgs { public static void main (String[] args) { if (args.length==0) { // there are no command like args System.out.println("mode 1"); System.out.println("we will do the interactive test driver"); } else { // there are command line args int pri; String assocData; System.out.println("mode 2"); System.out.print("here are the args: "); int na = args.length; // our test data will make this even for (int i=0; i < na; i+=2) { pri = Integer.parseInt(args[i]); assocData = args[i+1]; System.out.print(pri+":"); System.out.print(assocData+", "); } System.out.println(); } } }