import javax.servlet.*;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;

/**
 * Created by sergii on 23.07.14.
 */

@WebServlet(
        description = "Login Servlet",
        urlPatterns = { "/LoginServlet" },
        initParams = {
                @WebInitParam(name = "user", value = "Sergii"),
                @WebInitParam(name = "password", value = "somepassword")
        })


public class LoginServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;


    public void init() throws ServletException {
        //we can create DB connection resource here and set it to Servlet context
        if (getServletContext().getInitParameter("user").equals("auth_user") &&
                getServletContext().getInitParameter("userPwd").equals("authUser_pwd"))
            getServletContext().setAttribute("Success", "True");
        else throw new ServletException("Invalid credentials");
    }


    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //get request parameters for userID and password
        String user = request.getParameter("user");
        String pwd = request.getParameter("pwd");

        //get servlet config init params
        String userID = getServletConfig().getInitParameter("user");
        String password = getServletConfig().getInitParameter("password");
        //logging example
        log("User=" + user + "::password=" + pwd);

        if (userID.equals(user) && password.equals(pwd)) {
            response.sendRedirect("WEB-INF/LoginSuccess.jsp");
        } else {
            RequestDispatcher rd = getServletContext().getRequestDispatcher("/WEB-INF/login.html");
            PrintWriter out = response.getWriter();
            out.println("<font color=red>Either user name or password is wrong.</font>");
            rd.include(request, response);

        }

    }


    public void destroy() {
    }


}