Background: In my journey to become a good programmer I am creating a tic tac toe program in Java EE for web deployment. I have a good basic understanding of java and so started with the same program flow I had already. I moved it to a JSP (because that is what I had been working on). It is working fine there with some slight tweaks. Now I am getting it over to a servlet (because every post I read says that using JSP is not good and makes life hard on bigger programs).
Issue:
I have the board coming up, and it seems that the buttons I am using are good. However when I select one nothing happens. When I changed this from JSP to a servlet I got an error dealing with my Session.getAttribute. I removed it and all was well - minus not working. I think this could be my issue and so I am asking what am I doing wrong with it.
The error is saying "can not find symbol variable session" It asks me to create a field for session. If I remove this section then i need to initialize both "tiles" and "winner" but that puts them at null which is what I think my issue is.
If you want to see the entire code let me know and I will edit with it. Thank you for your time and the help.
public class TicTacToeServlet extends HttpServlet {
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
try (PrintWriter out = response.getWriter()) {
out.println("<HTML>");
out.println("<HEAD> Tic-Tac-Toe Boss");
out.println("</HEAD>");
out.println("<BODY>");
char[][] tiles; // the board that will hold buttons
String winner;
tiles = (char[][]) session.getAttribute("tiles"); //Here is the error
winner = (String)session.getAttribute("winner"); //Error - "can not find symbol Session"
if (tiles == null || winner == null) {
tiles = new char[3][3];
for (int r=0; r<3; r++)
for (int c=0; c<3; c++)
tiles[r][c] = ' ';
winner = new String("");
}
This is how it looks when I have it display but not change the buttons on click:
char[][] tiles = null; // the board that will hold buttons
String winner = null;
// Initialize if not already present in the session (i.e. after reset is hit)
if (tiles == null || winner == null) {
tiles = new char[3][3];
