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Redirect ModelAndView with message

My application has a method to update a conference. After doing so I have a modelandview with a redirect to the main conference list. This all works fine although the message which I add as an object to the modelandview does not display.
My method in my controller:
#PostMapping("/updateConference")
public ModelAndView updateConference(
#ModelAttribute("conference") #Valid ConferenceDto conferenceDto, BindingResult result) {
if(result.hasErrors()){
return new ModelAndView("updateConference","conferenceDto", conferenceDto);
}
try {
conferenceService.updateConference(conferenceDto);
} catch (ConferenceAlreadyExistException uaeEx) {
ModelAndView mav = new ModelAndView("updateConference","conferenceDto", conferenceDto);
mav.addObject("message", uaeEx.getMessage());
return mav;
}
ModelAndView mav = new ModelAndView("redirect:/teacher/configure"); // Problem is here
mav.addObject("message", "Successfully modified conference.");
return mav;
}
In my html I have the line:
<div th:if="${message != null}" th:align="center" class="alert alert-info" th:utext="${message}">message</div>
After updating the conference it goes back to configure.html although the message does not show. In the url I can see http://localhost:8080/teacher/configure?message=Successfully+modified+conference
I have looked at this thread although it did not help.
I tried to experiment by setting ModelAndView mav = new ModelAndView("configure") and the message displays but my conference list is empty and the url is http://localhost:8080/teacher/updateconference
Any tips is highly appreciated!
EDIT
I have tried to use RedirectAttributes as crizzis pointed out & this page and have this now:
#PostMapping("/updateConference")
public String updateConference(
#ModelAttribute("conference") #Valid ConferenceDto conferenceDto, BindingResult result, RedirectAttributes attributes) {
if(result.hasErrors()){
attributes.addFlashAttribute("org.springframework.validation.BindingResult.conferenceDto", result);
attributes.addFlashAttribute("conferenceDto", conferenceDto);
return "redirect:/teacher/updateConference";
}
try {
conferenceService.updateConference(conferenceDto);
} catch (ConferenceAlreadyExistException uaeEx) {
attributes.addFlashAttribute("conferenceDto", conferenceDto);
attributes.addFlashAttribute("message", uaeEx.getMessage());
return "redirect:/teacher/updateConference";
}
attributes.addFlashAttribute("message", "Successfully modified conference.");
return "redirect:/teacher/configure";
}
My get method:
#GetMapping(path = "/updateConference/{id}")
public String showUpdateConferenceForm(#PathVariable(name = "id") Long id, Model model){
Optional<Conference> conference = conferenceService.findById(id);
if (!model.containsAttribute("ConferenceDto")) {
model.addAttribute("conference", new ConferenceDto());
}
return "updateConference";
}
This works as intended and my message is shown on my configure.html . However, when I have an error in BindingResults the application goes to an error page and I get this in the console:
Resolved [org.springframework.web.HttpRequestMethodNotSupportedException: Request method 'GET' not supported]

Use RedirectAttributes which has addFlashAttribute method. You can set the success or failure message like you did and access that message through the key in the redirected page as you need.
when the error occurs you are redirecting to the same method instead of this you can just render the template in case there is error. I do this way.

Spring MVC ResquestMapping 'POST' not supported

I have a method with get and post in login controller. When application is deployed from index page i am redirecting to login page it makes GET request(/login.htm) it works fine but when i make post request with JSON body it says Request method 'POST' not supported i am using postman tool to test please
Help
#RequestMapping(value="/login",method = RequestMethod.GET)
public ModelAndView redirectLoginForm()
{
System.out.println("Login Page...");
return new ModelAndView("login");
}
#RequestMapping(value="/login",method=RequestMethod.POST,
consumes=MediaType.APPLICATION_JSON_VALUE,
produces=MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<Login> login(#RequestBody Login login)
{
System.out.println("Checking LoginCredentials...");
boolean isValid=loginServiceBo.checkUserLogin(login);
if(isValid)
{
return new ResponseEntity<Login>(login, HttpStatus.ACCEPTED);
}
return new ResponseEntity<>(login, HttpStatus.NOT_FOUND);
}

Taking in account your code:
#RequestMapping(value="/login",method=RequestMethod.POST,
consumes=MediaType.APPLICATION_JSON_VALUE,
produces=MediaType.APPLICATION_JSON_VALUE)
In the screenshot of Postman, is missing the correct mapping, it should be: http://localhost:8073/Spring_Hibernate_Project/login

I think it's connected with your postman query.
May be my screenshot will be helpful to check your postman, on server side I have very similar mapping.

Spring MVC : the best way to handle exception for Ajax Request and normal request?

I want to define a common exception manger in my project, so I use #ControllerAdvice to do, the snippet of code is below:
#ExceptionHandler(Exception.class)
public ModelAndView handleAllException(HttpServletRequest request, Exception ex) throws Exception
{
LOGGER.error(ex.getMessage());
ModelAndView mav = new ModelAndView();
mav.addObject("exception", ex);
mav.addObject("url", request.getRequestURL());
mav.setViewName(ViewConstants.INTERNAL_ERROR_VIEW);
return mav;
}
it will return a common error page. That's great for normal exception of request. But if this is a Ajax request, the result is so ugly. so I add the code to judge it. The added code is below:
if ("XMLHttpRequest".equals(request.getHeader("X-Requested-With"))) {
// return HTTP Status code and response message
} else {
// return error page name
}
I don't think it is the best way, anybody have a good opinion?

I have all my controllers in different packages based on whether they serve AJAX requests or not. Then I can set #basePackages element on the ControllerAdvice annotations to handle the exception accordingly
Update:
See RequestMapping#params and RequestMapping#headers to separate controllers based on headers and/or params

I would suggest to set error response code on any request, think this is a good practice to notify client that something goes wrong not depending on type of request. And for ajax request you can return same page and identify problem by error code.

If you use jQuery for making requests, you could use the following:
jQuery.ajaxSetup({
headers: { 'ajax-request': true },
statusCode: {
400: function (xhr) {
...do something
},
500: function (xhr) {
...do something
}
...
}
});

...
public class Application extends SpringBootServletInitializer {
#Bean(name = "simpleMappingExceptionResolver")
public SimpleMappingExceptionResolver createSimpleMappingExceptionResolver() {
SimpleMappingExceptionResolver r = new SimpleMappingExceptionResolver();
r.setDefaultErrorView("forward:/errorController");
return r;
}
#Controller
public class ErrorController {
public static final Logger LOG = Logger.getLogger(ErrorController.class);
#RequestMapping(value = "/errorController")
public ModelAndView handleError(HttpServletRequest request,
#RequestAttribute("exception") Throwable th) {
ModelAndView mv = null;
if ("XMLHttpRequest".equals(request.getHeader("X-Requested-With"))) {
if (isBusinessException(th)) {
mv = new ModelAndView("appAjaxBadRequest");
mv.setStatus(BAD_REQUEST);
} else {
LOG.error("Internal server error while processing AJAX call.", th);
mv = new ModelAndView("appAjaxInternalServerError");
mv.setStatus(INTERNAL_SERVER_ERROR);
}
mv.addObject("message", getUserFriendlyErrorMessage(th).replaceAll("\r?\n", "<br/>"));
} else {
LOG.error("Cannot process http request.", th);
mv = new ModelAndView("appErrorPage");
mv.addObject("exeption", th);
}
return mv;
}
}

Redirect with 301 status in Spring MVC 4 without ModelAndView

I try to have a redirect with 301 Status Code (you know I want to be SEO friendly etc).
I do use InternalResourceViewResolver so I wanted to use some kind of a code similar to return "redirect:http://google.com" in my Controller.
This though would send a 302 Status Code
What I have tried is using a HttpServletResponse to set header
#RequestMapping(value="/url/{seo}", method = RequestMethod.GET)
public String detail(#PathVariable String seo, HttpServletResponse response){
response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
return "redirect:http://google.com";
}
It does still return 302.
After checking documentation and Google results I've come up with the following:
#RequestMapping(value="/url/{seo}", method = RequestMethod.GET)
public ModelAndView detail(#PathVariable String seo){
RedirectView rv = new RedirectView();
rv.setStatusCode(HttpStatus.MOVED_PERMANENTLY);
rv.setUrl("http://google.com");
ModelAndView mv = new ModelAndView(rv);
return mv;
}
It does work perfectly fine and as expected, returning code 301
I would like to achieve it without using ModelAndView (Maybe it's perfectly fine though). Is it possible?
NOTE: included snippets are just parts of the detail controller and redirect does happen only in some cases (supporting legacy urls).

I would suggest using redirectView of spring like you have it. You have to have a complete URL including the domain etc for that to work, else it will do a 302. Or if you have access to HttpServletResponse, then you can do the below as below.
public void send301Redirect(HttpServletResponse response, String newUrl) {
response.setStatus(HttpServletResponse.SC_MOVED_PERMANENTLY);
response.setHeader("Location", newUrl);
response.setHeader("Connection", "close");
}

Not sure when it was added, but at least on v4.3.7 this works. You set an attribute on the REQUEST and the spring View code picks it up:
#RequestMapping(value="/url/{seo}", method = RequestMethod.GET)
public String detail(#PathVariable String seo, HttpServletRequest request){
request.setAttribute(View.RESPONSE_STATUS_ATTRIBUTE, HttpStatus.MOVED_PERMANENTLY);
return "redirect:http://google.com";
}

If you already return a ModelAndView and don't want to use HttpServletResponse, you can use this snippet:
RedirectView rv = new RedirectView("redirect:" + myNewURI);
rv.setStatusCode(HttpStatus.MOVED_PERMANENTLY);
return new ModelAndView(rv);

spring mvc #ExceptionHandler method get same view

My problem is that I want to create an #ExceptionHandler method that will capture all un-handled exceptions. Once captured I would like to redirect to the current page instead of specifying a separate page just to display error.
Basically how do I get the value of someview returned by somemethod and set it dynamically in the method unhandledExceptionHandler below.
#ExceptionHandler(Exception.class)
protected ModelAndView unhandledExceptionHandler(Exception ex){
System.out.println("unhandle exception here!!!");
ModelAndView mv = new ModelAndView();
mv.setViewName("currentview");
mv.addObject("UNHANDLED_ERROR", "UNHANDLED ERROR. PLEASE CONTACT SUPPORT. "+ex.getMessage());
return mv;
}
#RequestMapping(value = "/somepage", method = RequestMethod.GET)
public String somemethod(HttpSession session) throws Exception {
String abc = null;
abc.length();
return "someview";
}
So in JSP I can render this error message back into the current page something like that.
<c:if test="${not empty UNHANDLED_ERROR}">
<div class="messageError"> ${UNHANDLED_ERROR}</div>
</c:if>

I don't think there is way to do what you are asking for, because in the exception handler method unhandledExceptionHandler there is no way to find out what the name of the view that the handler method somemethod would have returned.
The only way is for you to introduce some sort of meta data scheme so that when you end up in the exception handler you can figure out what view to map it to. But I think this meta data scheme would be fairly complex. You can implement such a scheme by finding out what was the original url being accessed when the exception was thrown, this can be done with the code snippet below.
(ServletRequestAttributes) RequestContextHolder.currentRequestAttributes()).getRequest()
Once you know what the original request URL you can redirect to it, maybe using flash attribute to store the fact that there was an exception and what the error is.
The main problem wit the metadata will occur when you have a handler method that select between different views something like.
#RequestMapping(value = "/somepage", method = RequestMethod.GET)
public String somemethod(HttpSession session) throws Exception {
String abc = null;
if(someCondition) {
abc.length();
return "someview";
} else {
// do some stuff here.
return "someOtherView";
}
}
Even knowing that somemethod was the source of the error leaves you not knowing which branch in the if statement caused the exception.

I dont think you can do this without modifying all of your handler methods. However you can try to do this in a "pretty" way:
1) You can define your own annotation which will accept target view name as a parameter (e.g. #ExceptionView)
2) Next thing to do is marking your handler methods with it, e.g.:
#ExceptionView("someview")
#RequestMapping(value = "/somepage", method = RequestMethod.GET)
public String somemethod(HttpSession session) throws Exception {
String abc = null;
abc.length();
return "someview";
}
3) After that you can do something like this in exception handler:
#ExceptionHandler(Exception.class)
protected ModelAndView unhandledExceptionHandler(Exception ex, HandlerMethod hm) {
String targetView;
if (hm != null && hm.hasMethodAnnotation(ExceptionView.class)) {
targetView = hm.getMethodAnnotation(ExceptionView.class).getValue();
} else {
targetView = "someRedirectView"; // kind of a fallback
}
ModelAndView mv = new ModelAndView();
mv.setViewName(targetView);
mv.addObject("UNHANDLED_ERROR", "UNHANDLED ERROR. PLEASE CONTACT SUPPORT. "+ex.getMessage());
return mv;
}

Rather than sending the error on a separate page, you can you just put the error in the ModelAndView object. In your case you can just put the try/catch in your controller method and return the same view like so:
#RequestMapping(value = "/somepage", method = RequestMethod.GET)
public String somemethod(ModelAndView mv,HttpSession session) throws Exception {
mv.setViewName("someview");
try{
String abc = null;
abc.length();
} catch(Exception e) {
mv.addObject("UNHANDLED_ERROR", "UNHANDLED ERROR. PLEASE CONTACT SUPPORT. "+ex.getMessage());
}
return mv;
}
So add the ModelAndView to your method and return it.

I have not tried this out, but based on the documentation here, we can get the request object in the exception handler. We may not be able to get the view linked to the URL. Getting the view from the URL, and the state/model of the view will be the tricky part.
#ExceptionHandler(Exception.class)
public ModelAndView handleError(HttpServletRequest req, Exception ex) {
logger.error("Request: " + req.getRequestURL() + " raised " + ex);
ModelAndView mav = new ModelAndView();
mav.addObject("exception", ex);
mav.addObject("url", req.getRequestURL());
mav.setViewName("error");
return mav;
}

Create a controller method annotated with #RequestMethod("/server-error")
Create a controller method annotated with #ExceptionHandler which will return "forward:/server-error";