refactoring1.java

// Original functions
    public void returnBoardSize() {
        ui.requestBoardSize();
        String size = ui.returnBoardSize();
        if (tryParse(size)) {
            validateBoardSize(size);
            Integer intSize = Integer.parseInt(size);
            setBoardSize(intSize);
        } else {
            ui.invalidBoardSizeMessage(size);
            returnBoardSize();
        }
    }
    
    // Handles NumberFormatException
    private static boolean tryParse(String size) {
        try {
            new Integer(size);
            return true;
        } catch (NumberFormatException e) {
            return false;
        }
    }
// Refactored methods

    // Sets board size to GameSettings object when valid.
    public void setUpBoardSize() {
        String size = getBoardSizeFromUser();
        if (tryParse(size)) {
            validateBoardSize(size);
            setBoardSize(Integer.parseInt(size));
        } else {
            ui.invalidBoardSizeMessage(size);
            setUpBoardSize();
        }
    }
    
    // Shows bad input message and recursively calls setup method again if bad value.
    private void validateBoardSize(String size) {
        if ((Integer.parseInt(size) < MIN_BOARD_SIZE) || (Integer.parseInt(size) > MAX_BOARD_SIZE)) {
            ui.invalidBoardSizeMessage(size);
            setUpBoardSize();
        }
    }

    // Gets board size string from user
    private String getBoardSizeFromUser() {
        ui.requestBoardSize();
        return ui.returnBoardSize();
    }

    // Handles NumberFormatException
    private static boolean tryParse(String size) {
        try {
            new Integer(size);
            return true;
        } catch (NumberFormatException e) {
            return false;
        }
    }