Command line args for your java app!

[aadem]

Greetings everyone! I just posted my first post here on the intro forum yesterday, and am a fairly new (in my first year) java enthusiast and student. I find it extremely helpful for me to write myself a tutorial for everything i learn, even if its opening a simple 6 line text file in vim just to jot a reminder note. This helps me then in turn to convert what i just learned to permanent knowledge.

I have also noticed that because theres just plain a LOT of things you can do with Java , finding the 'perfect' tutorial or example for what you want to do can be tough sometimes. I had this problem with figureing out how to add command line arguments to my simple io apps. Using if statements i figured out how to make an app have arguments, but it was terribly ugly and the app could only run with as many arugments as i took the time to write a seperate block of if statements for. Finally i got the idea of a for loop and it works great! The prog can have as many arguments as the user wants to put in, if one isnt valid it will tell u and move on to the next. This is how i did it, and i hope this helps someone!! And if theres a better way to do this someone plz let me know :D

/*
* Java application designed to demonstrate simple arguments
* and show the ability to accept as many arguments as the user
* decides to input, independent of weather or not they are valid
*/

public class argDemo {
	
	public static void main(String[] argv) {

	    if (argv.length > 0) {
		System.out.println("This program has arguments");
		for (int i=0; i < argv.length; i++){
			if (argv[i].equals("-v")) {
				System.out.println("JavArg Demo v1.0");
			}
			else if (argv[i].equals("-a")) {
				System.out.println("All Possible Arguments: -v, -a, -x, -d");
			}
			else if (argv[i].equals("-x")) {
				System.out.println("You have chosen to exit the program early.");
				System.exit(0);
			}
			else if (argv[i].equals("-d")) {
				System.out.println("You have enabled debugging");
				System.out.println("Creating log files..");
				//write log files using filewriters wrapped in bufferedwriters
			}
			else {
				System.out.println(""+argv[i]+" is an invalid argument");
			}
		}  //End of for loop
	    }  //End of arg if statment
	

		System.out.println("Thank you for using JavArg Demo");
	

	}
}

[KevinWorkman]

Another way to do this is to simply form one large String out of the arguments and just check whether each is a substring of that large String.

Or you could convert the array to a List and use the contains() method.

[aadem]

why your absolutely right! i love these forums already im documenting those 2 methods right now it my little scratchbook haha! Thanks again i needed some homework on substrings anyhow, and need to investigate more into what methods are hidden down depe in the array datatype for my use