Array not equal to null when assigned null

arguments is not equal to null. Or there might be something else that I am missing.

The purpose of the code is to take any given String and handle the three different cases.

1. "doSomething" => invoke doSomething()


2. "doSomethingElse,2" => invoke doSomething(2)


3. "doSomethingElsePlease,3,4" => invoke doSomething(3,4)

Number 2 and 3 can both be handled with varargs and passing the arguments as an array. Number 1 is were the problem occurs. The error that occurs is that

h("doSomething"); is trying to call for doSomething(null) {...}

private void h (String abc) {       
    String method = (abc.indexOf(",") == -1) ? abc: abc.substring(0, abc.indexOf(","));
    System.out.println("Method: |" + method+"|");       
    String[] arguments = (abc.indexOf(",") == -1) ? null : abc.substring(abc.indexOf(",")).split(",");
    System.out.println("Arguments: " + Arrays.toString(arguments));

    try {
        if (arguments == null) {
            this.getClass().getMethod(method, String.class).invoke(this); 
        } else {
            System.exit(0);
            this.getClass().getMethod(method, String.class).invoke(this, Arrays.asList(arguments)); 
        }           
    } catch (IllegalAccessException | IllegalArgumentException
            | InvocationTargetException | NoSuchMethodException
            | SecurityException e) {
        e.printStackTrace();
    }
}