/**
* Typed request handlers simplify testing, no need to mock http response, request dispatcher or
* to handle exceptions.
*/
String handleRequest(ConnectFourRequest req) {
// Get elements from the session
ConnectFourSession session = req.getSession();
Game game = session.getGame();
// Create game or reset it if necessary
String resetStr = req.getParameter(PARAM_RESET_KEY);
if ((game == null) || (resetStr != null)) {
// TODO use dependency injection to avoid dependency on implementation
game = new GameImpl();
game.begin();
}
// Handle play parameter
String subMessage = "";
String colStr = req.getParameter(PARAM_PLAY_KEY);
if (colStr != null) {
try {
int colIdx = Integer.parseInt(colStr);
game.dropDisc(colIdx - 1);
} catch (NumberFormatException e) {
subMessage = "Invalid parameter col: " + colStr;
log.error(subMessage);
} catch (ConnectFourException e) {
subMessage = e.getMessage();
log.error(subMessage);
}
}
// Build main message
String mainMessage = "";
GameStatus gameStatus = game.getStatus();
if (gameStatus == GameStatus.ONGOING) {
Player player = game.getCurrentPlayer();
mainMessage = "Now playing: " + player.getName();
} else if (gameStatus == GameStatus.FINISHED) {
Player winner = game.getWinner();
if (winner != null) {
mainMessage = winner.getName() + " won the game.";
} else {
mainMessage = "It's a draw game.";
}
}
// Save request attributes for the view
req.setMainMessage(mainMessage);
req.setSubMessage(subMessage);
req.setGameId(game.getId());
// Save elements in the session
session.setGame(game);
return MAIN_DISPLAY_JSP;
}