How can I update my output on console in Java? (Right hand rule maze solver)

Question

I'm trying to solve maze by using right hand rule, and my algorithm seems pretty good to me. I have a little problem with my codes though. I want to update my output on console, but I really don't know how to do it. I kind of got the sense that I have to use Thread.sleep, but I don't know where to put it so that it can update my console constantly without printing whole new maze each move.

I want to make user can see the X's current position, and I want there's no trailing X. It's a bit hard to explain with just words, so I made an gif picture.

And here are my codes. Thank you for anyone who will answer my question! Have a nice day y'all :D

public class MazeTraversalGradedProgram {
    private static int row, column, count;
    private static String direction = "right";

private static char maze1 [] [] = {
    {'#','#','#','#','#','#','#','#','#','#','#','#'},
    {'#','.','.','.','#','.','.','.','.','.','.','#'},
    {'.','.','#','.','#','.','#','#','#','#','.','#'},
    {'#','#','#','.','#','.','.','.','.','#','.','#'},
    {'#','.','.','.','.','#','#','#','.','#','.','.'},
    {'#','#','#','#','.','#','.','#','.','#','.','#'},
    {'#','.','.','#','.','#','.','#','.','#','.','#'},
    {'#','#','.','#','.','#','.','#','.','#','.','#'},
    {'#','.','.','.','.','.','.','.','.','#','.','#'},
    {'#','#','#','#','#','#','.','#','#','#','.','#'},
    {'#','.','.','.','.','.','.','#','.','.','.','#'},
    {'#','#','#','#','#','#','#','#','#','#','#','#'}};

private static char maze2 [] [] = {
    {'#','#','#','#','#','#','#','#','#','#','#','#'},
    {'#','.','.','.','.','.','#','.','.','.','.','#'},
    {'#','.','#','.','#','.','#','#','#','#','.','#'},
    {'#','#','#','.','#','.','.','.','.','#','.','#'},
    {'#','.','.','.','.','#','#','#','.','#','.','#'},
    {'#','#','#','#','.','#','.','#','.','#','.','#'},
    {'#','.','.','#','.','#','.','#','.','#','.','.'},
    {'#','#','#','#','.','#','.','#','.','#','.','#'},
    {'#','.','.','.','.','#','.','.','.','#','.','#'},
    {'#','.','#','#','#','#','#','#','.','#','.','#'},
    {'.','.','#','.','.','.','.','#','.','.','.','#'},
    {'#','#','#','#','#','#','#','#','#','#','#','#'}};

private static void printMaze (char [] [] maze) {
    for (int i = 0; i<maze.length; i++) {
        for(int j = 0; j<maze[i].length; j++) {
            System.out.print(maze [i][j] + " ");
        }
        System.out.println();
    }
    System.out.println();
    System.out.println();
}

private static void goForward (char [] [] maze){
    if (direction == "right") {
        column++;
        maze[row][column] = 'X';
    } else if (direction == "up") { // array[xnd row --- ][ynd column | ]
        row--;
        maze[row][column] = 'X';
    } else if (direction == "left") {
        column--;
        maze[row][column] = 'X';
    } else if (direction == "down") {
        row++;
        maze[row][column] = 'X';
    }
}
private static boolean wallOnRight (char [] [] maze) {
    if (direction == "right" && maze[row+1][column] == '#') {
        return true;
    }
    else if (direction == "up" && maze[row][column+1] == '#') {
        return true;
    }
    else if (direction == "left" && maze[row-1][column] == '#') {
        return true;
    }
    else if (direction == "down" && maze[row][column-1] == '#') {
        return true;
    }
    return false;
}

private static boolean wallOnFront (char [] [] maze) {
    if (direction == "right" && maze[row][column+1] == '#') {
        return true;
    }
    else if (direction == "up" && maze[row-1][column] == '#') {
        return true;
    }
    else if (direction == "left" && maze[row][column-1] == '#') {
        return true;
    }
    else if (direction == "down" && maze[row+1][column] == '#') {
        return true;
    }
    return false;
}

private static void traverseMaze (char [] [] maze){

    if (count == 0) {
        for (int i = 0; i < 12; i++) {
            if (maze[i][0] == '.'){                 // array[xnd row --- ][ynd column | ]
                maze[i][0] = 'X';
                row = i; column = 0;
            }
        }
        count++;
    }

    if (wallOnRight(maze) && !wallOnFront(maze)) {
        goForward(maze);
    } else if (wallOnRight(maze) && wallOnFront(maze)) {
        if (direction == "right") {
            direction = "up";
        } else if (direction == "up") {
            direction = "left";
        } else if (direction == "left") {
            direction = "down";
        } else if (direction == "down") {
            direction = "right";
        }
    } else if (!wallOnRight(maze)) {
        if (direction == "right") {
            direction = "down";
        } else if (direction == "up") {
            direction = "right";
        } else if (direction == "left") {
            direction = "up";
        } else if (direction == "down") {
            direction = "left";
        }
        goForward(maze);
    }

    if (column == 11) {
        count = 0 ;
    } else {
        traverseMaze(maze);
    }


}

public static void main (String [] args){
    printMaze(maze1);
    traverseMaze(maze1);
    printMaze(maze2);
    traverseMaze(maze2);
}

}

You cannot update console. You will need some type of GUI for that. — PM 77-1, Nov 20 '19 at 23:59
@PM77-1 What I mean by that, is constantly updating outputs like my GIF picture. I could find some cases that updating outputs with using ```Thread.sleep``` command and while loops or for loops, but I really couldn't find any with 2D array. Thank you for your comment! — Joshua Chang, Nov 21 '19 at 00:24
You can't **reliably** do this on every platform that Java is supported on. It is completely dependent upon what is interpreting the code and producing your **output**. There are some libraries and commands you can use to move your cursor around in the console...but again, these are dependent upon the environment in which Java is being run. — Idle_Mind, Nov 21 '19 at 00:45
As mentioned from @JoshuaChang you cannot **clean** the console in Java, BUT you can redraw the whole screen after every input, see https://stackoverflow.com/questions/58987624/java-text-based-maze-game/59261042#59261042 — Martin Frank, Dec 10 '19 at 05:57

How can I update my output on console in Java? (Right hand rule maze solver)

0 Answers0