On my device, the snake game seems to stutter. Maybe it is too slow(it is quite old). I guess the problem is the print method? (not quite sure, though) I tried to make the print method run faster but I am not quite satisfied yet. The way I am iterating through the snake's body is bugging me, I guess this take a long time. But I can't really figure out a better way to do so. Maybe you have better ideas? I appreciate your help.
public void print() {
        StringBuilder builder = new StringBuilder();

        for(int y = 0; y < height; y++){
            builder.append("\n");
            for(int x = 0; x < width; x++){

                //I don't like this part:
                boolean body = false;
                for(int i = 1; i < snake.getSections().size(); i++){
                    if(snake.getSections().get(i).getY() == y && snake.getSections().get(i).getX() == x){
                        body = true;
                    }
                }
                //

                if(y == snake.getY() && x == snake.getX()){
                    builder.append("X");
                }
                else if(body == true){
                    builder.append("x");
                }
                else if(y == mouse.getY() && x == mouse.getX()){
                    builder.append("^");
                }
                else{
                    builder.append(".");
                }
            }
        }
        System.out.println(builder);