Server.java

package com.example.server;

import java.io.IOException;
import java.sql.*;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class Server extends HttpServlet {

  static final String DB_URL = "jdbc:mysql://localhost/users";
  static Connection conn;

  @Override
  protected void doGet(HttpServletRequest req, HttpServletResponse resp)
      throws ServletException, IOException {
    Cookie c = new Cookie("uid", req.getSession().getId());
    // For older browsers?
    c.setSecure(false);
    resp.addCookie(c);
    resp.setHeader("Access-Control-Allow-Origin", "*");

    Boolean b = Boolean.parseBoolean(req.getParameter("winCondition"));
    int ticketNumber = Integer.parseInt(req.getParameter("ticket"));
    try {
      Statement s = conn.createStatement();
      s.execute("SELECT userName, isWin FROM users WHERE uid = " + ticketNumber + ";");
      ResultSet r = s.getResultSet();

      if (r.getBoolean("isWin") && b) {
        resp.getWriter().write("You win, " + r.getString("userName"));
      } else {
        resp.getWriter().write("You lose, " + r.getString("userName"));
      }
    } catch (SQLException throwables) {
      throwables.printStackTrace();
    }
    resp.setStatus(200);
  }

  @Override
  protected void doPost(HttpServletRequest req, HttpServletResponse resp)
      throws ServletException, IOException {
    super.doPost(req, resp);
  }

  @Override
  public void destroy() {
    super.destroy();
  }

  @Override
  public void init() throws ServletException {
    super.init();

    try {
      conn = DriverManager.getConnection(DB_URL, "user", "");
    } catch (SQLException throwables) {
      throwables.printStackTrace();
    }
  }
}