JUnit test case for checking arguments
<p><em>Edited</em>
I am learning how to write testcases using JUnit. Disclaimer: I haven't understood anything that I have found on the net regarding this. :)
I wish to write a simple test case for this:
I have a simple Java class that accepts arguments as parameters to the main function and prints it. There is no more to this code.
Edit:</p>

<p>This is my main function:
    public static void main(String args[]) {</p>

<pre><code>    //Expecting 3 arguments: 1. InputDirectory path, 2. OutputDirectory path, 3. Keys-comma separated

    checkArguments(args);
</code></pre>

<p>.....</p>

<pre><code>private static void checkArguments(String[] args) {
    // TODO Auto-generated method stub
    if (args.length != 3) {
        try {
            System.out.println("Invalid input arguments");
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return;
    }
}
</code></pre>

<p>}</p>

<p>This main function code works well. Now I need to write a test case such that I check how many inputs are there and accordingly print the message.
So far, I have written this:</p>

<pre><code>FilterProcessPDK checkArg = new FilterProcessPDK();
int testCheckArgRes = checkArg.checkArguments(); //I dont know how to pass the arguments to this function

@Test
public void testCheckArgs(){
    assertEquals("message", expected, actual);
}
</code></pre>

<p>For this, I will be giving the inputs- 1) Input path (C:/xyz/input) 2) Output path (C:/xyz/output) 3) A list of any number of "keys" ("A" or "A, j")</p>