Question

I have a main method that creates an instance of a logic class

 public static void main(String[] args) {
        try {
            Logic logic = new Logic(args[0]);
            ....... do some stuff here

        } catch (Exception e) {
            System.out.println("Error Encountered Details: " + e);
        }
    }

the thing is that the programme requires a csv file to run, i have put it in the same directory as the .jar file but when i run from the command line i just get java.lang.arrayindexoutofbounds(0) error

what am i doing wrong

thanks

Answer 1

Your command line should look like:

java -cp {name_of_jar} {name_of_class} {name_of_csv}

It looks like you’re not supplying the .csv file name (which will go in args[0]) ?

The above assumes that the main class is not defined in your .jar manifest. if it is, then use:

java -jar {name_of_jar} {name_of_csv}

It’s a good practise to check the args[] array for the required info, btw, and generate a message such as “Missing .csv file name” or similar to avoid a nasty exception/stack trace.