Other kinds of Argument checking

So we've talked about a possible argument checking in Java. What if you just want to pass in files to be worked on?

That's simple enough, just loop through your argument array and perform the work on the files in question. Here's a simple way of doing that.

public static void main(String[] args) {
    for (String arg : args) {
    	doSomethingSpecial(arg);
    }
}

You can easily save the results back out to the same file as well since you will have that current argument in your posession. Easy right? Yeah something like that.

What if you want to perform an action based if an argument is passed in?

Let's say that you pass the filename as the first argument, then you pass the operations you wish to perform on that argument in the following arguments.

You can easily get the first argument by doing args[0], and then you can put the remaining arguments in a HashSet and check one by one if the specified argument is there. If it is, then perform the specified operation on it that you define in your codebase. Let me see if I have an example of this:

public static void main(String[] args) {
        Set arguments = new HashSet<>(Arrays.asList(args));
        if (arguments.contains("doit")) {
            System.out.println("Doing it!");
        }
    }

Yep I did have an example. How's that for something? It all works out in the end. You can of course modify the code based upon whatever circumstance you need to work with.