I'm doing a little project with Spring 3 MVC & jQuery
I'm not sure how to ask it so i'll try to explain
I have this scenario :
LoginPage(with User object model) ---submit--> Server sends OK back to LoginPage -->
(LoginPage) redirect to Page2 using window.location = "Page2"
Problem : Page 2 doesn't recognize User
How to make it work? I tried reading about #SessionAttributes but didn't really understand it.
#Controller
public class LoginController {
...
...
#RequestMapping(value = "/")
public ModelAndView loginPage(ModelMap model) {
model.addAttribute("user", new User());
logger.info("Loading Login Page");
return new ModelAndView("login");
}
#RequestMapping(value = "/loginSubmit.html" ,method=RequestMethod.GET)
public String processSubmit( ModelMap model, User user) throws InterruptedException{
...
...
return "1" to login page
...
...
Here I want User user to be known from last controller,but it's making a new one instead.
#Controller
public class Controller2 {
#RequestMapping(value = "/home")
public String home(ModelMap model, User user) {
...
...
}
LoginPage.jsp
$.get("loginSubmit.html", form1Var.serialize(), function(data){
var isSucess = data.charAt(0) == "1" ? true : false;
if ( isSucess == true) {
alert("ok...");
window.location = "home";
}
EDIT Moved my solution to Answers.
By default the server side in Spring MMVC is stateless. To save state between requests you must put the data you want to save in the session. This data is then available for every request in the same session (i.e. from the same client).
In the solution you found, the #SessionAttributes("user") annotation has told Spring MVC to that you want the user object to be persisted across requests by saving it in the session. This is how Spring abstracts you from all the work of actually maintaining the state yourself.
My Solution :
#SessionAttributes("user")
on both controllers
and
#ModelAttribute("user") User user
as param in the method - worked
I'v also added
#ExceptionHandler(HttpSessionRequiredException.class)
public String SessionException(HttpSessionRequiredException ex) {
logger.info(ex.getMessage());
return "redirect:LogIn";
}
to catch Exception and the user will go to LoginPage instead of a exception error page
As Donal Boyle pointed , conclusion : use #SessionAttributes to share models between Controllers
Related
I have integrated payment gateway now, on success URL I want to pass some data from one controller to another controller but it's not working properly it's showing null value sometimes so, What I have to use instead of Session or TempData.
public void Index(UserRegistreModel model)
{
TempData["model2"]= model;
redirecturl += "&return=" + ConfigurationManager.AppSettings["SuccessURL"].ToString();
}
public ActionResult AnotherControllerMethod(UserRegistreModel model)
{
UserRegistreModel add = (UserRegistreModel) TempData["model2"];
//not getting any values
}
Your are adding User type class to Temp Data but you are extracting UserRegistreModel type so, that's why this was empty, Use like this :-
public void Index(User model)
{
TempData["model2"]= model;
redirecturl += "&return=" +
ConfigurationManager.AppSettings["SuccessURL"].ToString();
}
public ActionResult AnotherControllerMethod(User model)
{
User add = (User) TempData["model2"];
//not getting any values
}
How u are Passing Data ? Is it a forward or redirect? Forward will take the current data of your Request Object as it is the same Request but ur URL will not be changed in client.
And If u are redirecting then its a new Request. In This case the response will go to the client first (browser) then come to your new controller. As it is a new request, it will not have the old data from your calling controller.
Spring Has a special type of pojo called RedirectAttributes for this. Where you can add FlashAttribute for this type of requirement. Check the similar thing in .net
I have deployed a web application using Apache tomcat 8, java 8 and centos server in production.
When i tested the system by 5-6 users concurrently in office network everything seemed ok. But in client network, one users info is getting by another user(session attributes are shared/mixup). For example, if user A logs in, after a while his name is showing user B, who is logged in from different computer. If user presses Ctrl+R then his/her previous session restores for a while.
N.B. this scenario never happens other than that client network. They are using specific proxy. Other than proxy, this scenario does not happen.
I have a simple LoginController class without defining any scope. Some code snippets are below:
1. Login GET method:
#RequestMapping(value = "/login", method = RequestMethod.GET)
public String getLogin(#ModelAttribute LoginForm loginForm)
{
return "login";
}
2. Login POST method:
#RequestMapping("/login", RequestMethod.POST)
public String Login(#ModelAttribute LoginForm loginForm, HttpSession session)
{
User dbUser = this.userService.getUser(loginForm.getUserID());
if (dbUser != null)
{
if(passwordCheckedSuccess(dbUser.getPassword(), loginForm.getPassword()))
{
session.setAttribute("userName", dbUser.getUserName());
session.setAttribute("userId", dbUser.getUserId()); // primary key of user class
return "dashboard";
}
else
{
return "login";
}
}
}
3. I have created a loginIntercptor class to filter secured pages:
public class LoginInterceptor extends HandlerInterceptorAdapter
{
#Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception
{
if (!request.getRequestURI().endsWith("/login"))
{
if (request.getSession().getAttribute("userId") == null)
{
response.sendRedirect(request.getContextPath() + "/login");
return false;
}
}
return true;
}
}
I am not using spring security.
Please suggest a way to get rid of it. Thanks.
I am asking this because after long time searching I haven't found a good answer on this yet...
Here is what I want:
Example: I have a domain model "JobPosting" which a user should be able to change state to published, if it is still a draft. Before publishing I must not only validate the model properties I must also validate many different requirements regarding the user account, it's registered company etc. All this validation logic is put into a service layer. So far so good...
This is how my service layer looks like:
public IValidationResult ValidatePublish(JobPosting jobPosting){
...
}
public void Publish(JobPosting jobPosting){
jobPosting.State = JobPostingState.Published;
...
}
Any my controller:
public ActionResult Publish(PublishViewModel model){
...
var validationResult = _jobService.ValidatePublish(jobPosting);
if(validationResult.Success){
_jobService.Publish(jobPosting);
...
}
...
}
And here now my questions:
I want to be able to call the ValidatePublish from the controller to show validation errors in the view. However I must never be able to publish a job when validation fails.
So to have my code more robust I added a second validation check in my Publish method in service layer:
public void Publish(JobPosting jobPosting){
if(ValidatePublish(jobPosting).Success){
jobPosting.State = JobPostingState.Published;
...
}
}
but I have not such a good feeling with this approach because now I am calling the validation twice when validation is OK during each controller publish request.
What do you think. Is the second call to much? Is there a better approach?
I am asking because my whole application looks like that and if I would ever forget a validation call in controller I might end up with an not allowed domain model state in database. That's why I added the second validation check in each service method.
Thanks in advance for your thoughts on this!!!
One quick solution might be to have the Publisher class require the JobPosting and IValidationResult objects as arguments.
public void Publish(JobPosting jobPosting, IValidationResult validation)
{
if (validation.IsValid)
{
jobPosting.State = JobPostingState.Published;
// other work here...
}
}
Your Controller can then call the Validator, receive an IValidationResult and pass that back to the presentation layer if needed. Otherwise pass on to Publisher
public ActionResult Publish(PublishViewModel model)
{
var validationResult = _jobService.ValidatePublish(jobPosting);
if(validationResult.Success) _jobService.Publish(jobPosting, validationResult);
else return View("error", validationResult);
}
Edit:
A cleaner solution may be to have the Publisher class return a PublishAttempt result.
public class PublishAttempt : IValidationResult
{
public enum AttemptOutcome {get; set;}
}
public ActionResult Publish(PublishViewModel model)
{
var attempt = _jobService.Publish(jobPosting);
if (attempt.Success) return View("success");
else return View("error", attempt.ValidationResults);
}
The following just came into my mind... what do you think:
I change my service method to:
public IValidationResult Publish(JobPosting jobPosting, bool validateOnly = false){
var validationResult = ValidatePublish(jobPosting);
if(validateOnly) return validationResult;
jobPosting.State = JobPostingState.Published;
...
return validationResult;
}
And then in controller I always call only the Publish method and not the extra ValidatePublish anymore:
public ActionResult Publish(PublishViewModel model)
{
var validationResult = _jobService.Publish(jobPosting);
if(!validationResult.Success) return View("error", validationResult);
}
And when I need only simple validation I do
var validationResult = _jobService.Publish(jobPosting, true);
Is this okey to do it like that?
Or is it not good looking if a normal service call returns IValidationResult?
This is my controller code:
private string testVal;
public ActionResult Index()
{
testVal = "test";
return View();
}
public ActionResult NextView()
{
if (testVal == null)
Debug.WriteLine("testVal is null");
return View();
}
Is it possible to remeber values like testVal after changing page? It seems that when redirecting it resets values (testVal in NextVal is null).
Edit:
I try to save values to session but Session is null. I am using SignalR and when user is connected to page i use static event from hub to inform controller that user has connected - but inside method that runs on that event Session is unfortunetly null.
My controller code:
public ActionResult Index()
{
LoadingHub.userConnected += new EventHandler<IdEventArgs>(UserConnected);
return View();
}
private void UserConnected(object sender, IdEventArgs e)
{
Debug.WriteLine("User Connected with Id: " + e.Id);
if (Session == null)
Debug.WriteLine("Session is null");
}
My signalr hub:
public class LoadingHub : Hub
{
public static event EventHandler<IdEventArgs> userConnected;
//Function informs server that user has connected
public void Connected()
{
Debug.WriteLine("Hub Connected Method");
var id = Context.ConnectionId;
userConnected(this, new IdEventArgs(id));
}
}
Every time that you make a request a new instance of the controller is created so using a private field you will not be able to retain the value of this variable.
The easiest way for you to retain it it is to use a session. (if you want to retain this value per user base)
for example in your code
public ActionResult Index()
{
System.Web.HttpContext.Current.Session["testVal"] = "test";
return View();
}
public ActionResult NextView()
{
if (System.Web.HttpContext.Current.Session["testVal"] == null)
Debug.WriteLine("testVal is null");
return View();
}
you can use cookie or cache to replace the variable.
when you redirect to a webpage ，the controller will be newed ,so you cannot get the right testVal .but the cookie is stored in broswer .so you can set it and get .
You may use session or Pass the data to the controller
Have you looked into ASP.NET server side state management click here.
These are basically different ways to remember a value on the server once a new page has been loaded.
So a few server side techniques you could use to remember testVal are Session State or Application State. However Session State is more suitable for your scenario as it is only specific to the user's current session whereas Application State stores data that can be shared between sessions and would therefore be more ideal for global variables.
You can read the link I provided to read more on the differences though.
I would also like to warn you (as some say to use cookies), the user can delete or disable or manipulate them on the browser so this isn't an ideal solution.
I have a spring MVC based web application. Currently in my web page i am showing the user first name and last name after user logs in. The way i am doing this is, for every HttpServletRequest that comes into #Controller#RequestMapping, i get the Principal object and get the user details from it, then populate the ModelMap with firstname and lastname attribute. For example here is the sample code
#Autowired
private SecurityDetails securityDetails;
#RequestMapping(method = RequestMethod.GET)
public String showWelcomePage(HttpServletRequest request,
HttpServletResponse response, ModelMap model, Principal principal)
{
securityDetails.populateUserName(model, principal);
... lot of code here;
return "home";
}
public boolean populateUserName(ModelMap model, Principal principal) {
if (principal != null) {
Object ob = ((Authentication)principal).getPrincipal();
if(ob instanceof MyUserDetails)
{
MyUserDetails ud = (MyUserDetails)ob;
model.addAttribute("username", ud.getFirstName() + " " + ud.getLastName());
}
return true;
}
else
{
logger.debug("principal is null");
return false;
}
}
My problem is i am having to call the populateUserName method for every RequestMapping. Is there a elegant way, like populating this in Interceptor method, which will result in this method being called just in one place for entire application?
Its good that you want to prevent duplication of code. Here is how you can do it.
Create a custom HandlerInterceptor http://static.springsource.org/spring/docs/2.5.x/api/org/springframework/web/servlet/HandlerInterceptor.html
Post handle is the only method of interest for us, for the others return defaults.
In the post handle method, you have access to the model and view returned from your controller, go ahead and add whatever you want.
The Principal will not be available directly here, you will have to look it up using some code like SecurityContextHolder.getContext().getAuthentication().getPrincipal()
Wire the handler interceptor to intercept all or some of your controllers.
Hope this helps.
You can use either Servlet Filters or Spring Interceptors.
BTW, where do you populate the Principal from?
In any case, thats where you should do this populating stuff.