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| author | Sven Eisenhauer <sven@sven-eisenhauer.net> | 2023-11-10 15:11:48 +0100 |
|---|---|---|
| committer | Sven Eisenhauer <sven@sven-eisenhauer.net> | 2023-11-10 15:11:48 +0100 |
| commit | 33613a85afc4b1481367fbe92a17ee59c240250b (patch) | |
| tree | 670b842326116b376b505ec2263878912fca97e2 /Master/Reference Architectures and Patterns/EJB 3.0 Code/Gerald Examples/src/examples/shop/web/servlet/LoginServlet.java | |
| download | Studium-master.tar.gz Studium-master.tar.bz2 | |
Diffstat (limited to 'Master/Reference Architectures and Patterns/EJB 3.0 Code/Gerald Examples/src/examples/shop/web/servlet/LoginServlet.java')
| -rw-r--r-- | Master/Reference Architectures and Patterns/EJB 3.0 Code/Gerald Examples/src/examples/shop/web/servlet/LoginServlet.java | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/Master/Reference Architectures and Patterns/EJB 3.0 Code/Gerald Examples/src/examples/shop/web/servlet/LoginServlet.java b/Master/Reference Architectures and Patterns/EJB 3.0 Code/Gerald Examples/src/examples/shop/web/servlet/LoginServlet.java new file mode 100644 index 0000000..0340fd9 --- /dev/null +++ b/Master/Reference Architectures and Patterns/EJB 3.0 Code/Gerald Examples/src/examples/shop/web/servlet/LoginServlet.java @@ -0,0 +1,166 @@ +package examples.shop.web.servlet;
+
+import java.io.IOException;
+
+import javax.ejb.EJB;
+import javax.naming.Context;
+import javax.naming.InitialContext;
+import javax.servlet.RequestDispatcher;
+import javax.servlet.ServletConfig;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.http.HttpSession;
+
+import examples.shop.logic.Cart;
+import examples.shop.logic.UserManager;
+
+/**
+ * This is the very first servlet the client deals with. It's a Login
+ * authentication servlet and asks the user for his name and password,
+ * and pass it to the UserManager stateless session bean for verificatiion.
+ *
+ * If the user authenticates properly, a reference to a new Cart is saved
+ * in his HttpSession object, and the user can begin to add items to his
+ * cart and shop around.
+ */
+public class LoginServlet extends HttpServlet {
+
+ /** the user manager used to authenticate the user */
+ @EJB
+ UserManager userManager;
+
+ /** the user's cart object */
+ @EJB
+ Cart cart;
+
+ /**
+ * The servlet engine calls this method once to initialize a servlet
+ * instance.
+ */
+ public void init(ServletConfig config) throws ServletException {
+ super.init(config);
+ try {
+ /*
+ * Get the initial context using the above startup params.
+ */
+
+ Context ctx = new InitialContext();
+ userManager = (UserManager) ctx.lookup(UserManager.class
+ .getName());
+ cart = (Cart) ctx.lookup(Cart.class.getName());
+
+ } catch (Exception e) {
+ log(e);
+ throw new ServletException(e.toString());
+ }
+ }
+
+ /**
+ * The servlet engine calls this method when the user's desktop browser
+ * sends an HTTP request.
+ */
+ public void service(HttpServletRequest request, HttpServletResponse response)
+ throws ServletException, IOException {
+ /*
+ * Set up the user's HttpSession
+ */
+ HttpSession session = request.getSession(true);
+
+ System.out.println(request.getAttributeNames().toString());
+ /*
+ * Retrieve the login name / password from the URL string.
+ */
+ String loginName = request.getParameter("Login");
+ String password = request.getParameter("Password");
+ boolean isLogin = false;
+
+ /*
+ * If user has not tried to log in yet, present him with the login
+ * screen.
+ */
+ if ((loginName == null) || (password == null)) {
+ writeForm(request, response, false);
+ return;
+ } else {
+ /*
+ * Otherwise, the user has been to this screen already, and has
+ * entered some information. Verify that information.
+ */
+ try {
+ isLogin = userManager.validateUser(loginName, password);
+ } catch (Exception e) {
+ writeForm(request, response, true);
+ e.printStackTrace();
+ return;
+ }
+ /*
+ * If the passwords match, make a new Cart Session Bean, and add it
+ * to the user's HttpSession object. When the user navigates to
+ * other servlets, the other servlets can access the HttpSession to
+ * get the user's Cart.
+ */
+ if (isLogin) {
+ try {
+ cart.setOwner(loginName);
+ cart.clear();
+ session.setAttribute("cart", cart);
+
+ /*
+ * Call the main page
+ */
+ RequestDispatcher disp = this.getServletContext()
+ .getRequestDispatcher("/wsf.jsp");
+ disp.forward(request, response);
+
+ return;
+ } catch (Exception e) {
+ log(e);
+ throw new ServletException(e.toString());
+ }
+ } else
+ writeForm(request, response, true);
+ }
+
+ /*
+ * If there was no match, the user is not authenticated. Present another
+ * login screen to him, with an error message indicating that he is not
+ * authenticated.
+ */
+ writeForm(request, response, true);
+ }
+
+ /**
+ * Writes the Login Screen (private use only)
+ *
+ * @param showError
+ * true means show an error b/c client was not authenticated last
+ * time.
+ */
+ private void writeForm(HttpServletRequest request,
+ HttpServletResponse response, boolean showError)
+ throws ServletException, IOException {
+
+ /*
+ * Set a variable indicating whether or not we failed to log-in. The JSP
+ * will read this variable.
+ */
+ request.setAttribute("loginFailed", new Boolean(showError));
+
+ /*
+ * Forward the request to the login JSP
+ */
+ RequestDispatcher disp = this.getServletContext().getRequestDispatcher(
+ "/login.jsp");
+ disp.forward(request, response);
+ }
+
+ private void log(Exception e) {
+ e.printStackTrace();
+ }
+
+ public String getServletInfo() {
+ return "The Login servlet verifies a user.";
+ }
+}
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