Use a external file in my program

[romina]

I have just created a simple class that can "draw" integers on 20x20 2d array. (some of you may be familiar with the Turtle.java assignment, well, I'm just making a really simple version of that right now).

Currently I issue commands through the main method as follows:

Code:

      Turtle Romina = new Turtle();
        Romina.setStage();
        Romina.moveEast(5);
        Romina.moveNorth(5);
        Romina.setPenState("u");
        Romina.moveWest(5);
        Romina.setPenState("d");
        Romina.moveSouth(5);
        System.out.println(Romina.getArray());

this would output somthing like a 20x20 array of 0's with a square in the middle drawn with 1's (excluding the top part of the square because the "pen" is lifted during that part).

The output appears as expected. Perfect.
Now, I would like to issue those commands through an external file.
The commands would be as follows:

Code:

u = pen up
d = pen down
n10 = move up 10 spaces
e100 = move right 100 spaces
...
...
etc.

I can read from the external file, but I am not sure how to handle the data. Currentley I wrote this bit of code that breaks the file down by line:

Code:

        try {
            /**Read the specified file to give the turtle Directions*/
            BufferedReader turtleBrain = new BufferedReader(new FileReader("C:\\iTurtle.txt"));
            
            /**Seperate the file by line*/
            String thought;
            while ((thought = turtleBrain.readLine()) != null){
                //just for testing
		System.out.println(thought);
            }
            
        } catch (FileNotFoundException ex) {
            System.out.println("File not found");
        } catch (IOException ex){
            System.out.println("IO ERROR");
        }

Now, in that while loop I will check each line (i was thinking of using a switch/case) to call a certain method.
i.e. case "u" will call setPenState with the parameter "u".
The above is pretty straight forward, I don't have any trouble with that... What I would like some guidance on are the movements:

for example:
the line read = n8
I will have: case "n" that calls moveNorth and sends it the parameter "8".

Right now I a messing around with grabbing the line as a string, remove and check the first charater using RegEx, and if the first char is n, s, e, or w (North, South, East, West) parseInt the following number and send it to the appropriate method.
I have a feeling there is a better way to do this.

The iTurtle.txt file would contain somthing like:

Code:

u
d
n13
s10
e3
w9
u
e3
n5
d
s7
u
q

Thanks

[trill]

Why not put a character or space in between the command and parameter? That way you can utilize Java's Split function and do something like the below.

iTurtle.txt

Code:

U
D
N-13
S-10
E-3
W-9

Sample Java code

Code:

enum Commands {U, D, N, S, E, W};
String thought;
while ((thought = turtleBrain.readLine()) != null){
  String[] instructions = thought.split("-");
  Commands com = instructions[0];
  switch (com) {
    case U: Romina.setPenState("u"); break;
    case D: Romina.setPenState("d"); break;
    case N: Romina.moveNorth(instructions[1]); break;
    case S: Romina.moveSouth(instructions[1]); break;
    case E: Romina.moveEast(instructions[1]); break;
    case W: Romina.moveWest(instructions[1]); break;
    default: System.out.println("Invalid Command"); break;
  }
}

Greetings.