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Spring Boot Override Wildcard RequestMapping

I am building a URL Shorter app (like Bitly). It is an SPA using Spring Boot & ReactJS. All web content is served off of index.html. All other routes are presumed to be shortLink redirect requests which should trigger a clickShortUrl() function to fetch the corresponding originalLink and redirect the user to that web address.
Therefore, I want the following routes to redirect to index.html:
#GetMapping(value = {"/", "/home", "/dashboard"})
public String redirect() {
return "forward:/index.html";
}
and all other/unknown routes to trigger a wildcard function:
#RequestMapping(value = "/{shortUrl}", method = RequestMethod.GET)
public Object clickShortUrl(#PathVariable("shortUrl") String shortUrl, #RequestBody ClickDTO request) {
// internalLogicHere
};
Individually, the mappings and functions are working. But combined, the /{shortUrl} wildcard route always takes precedence. I've googled around looking for ways to override this behavior. It seems to be possible a few ways, but all of my attempts have failed.
I read several posts like this suggesting to extend WebMvcConfigurerAdapter and override addViewControllers(ViewControllerRegistry registry) to define view controllers for specific routes. I don't really understand this. Is this the right path? If so, can someone help me understand what ViewControllerRegistry is all about and set me on the right path?
Thank you!

Answered my own question. Ended up using RegEx in the wildcard route to exclude the static paths used on the front end.
/** Redirect all '/' and '/dashboard/ requests to index.html. */
#GetMapping(value = {"path:/", "path:/dashboard"})
public String redirect() {
return "forward:/index.html";
}
and the fallback route:
/**
* Treat all routes as /{shortUrl} clicks except: '/', '/index.html, '/dashboard''
*/
#RequestMapping(value = "{_:^(?!index\\.html|dashboard).*$}")
public Object clickShortUrl(#PathVariable("shortUrl") String shortUrl, #RequestBody ClickDTO request) {
// internalLogicHere;
}

How to get URI value coming from HTML to Variable in Spring (There are multiple Links associated with corresponding method)

I have multiple links in my HTML, which are referring to URI in Controller Class,
How can I get this URI in some variable which can be used further, at last, I want to store these URI in DB.
HTML Code :
<td>Win Report</td>
<td>Win Report</td>
Spring Controller Class :
#RequestMapping(value = "/ui/report/win", method = RequestMethod.GET)
public String winReport() {
return "win_report";
}
#RequestMapping(value = "/ui/report/niw", method = RequestMethod.GET)
public String niwReport() {
return "niw_report";
}

You can use the below solution to retrieve the page Url as well as avoid using repetitive method calls.
You can use a Spring Boot HandlerInterceptor, here's a brief description of the same :
Handler interceptors are used when you want to apply specific
functionality to certain or all requests.
Handler Interceptors should implement the interface HandlerInterceptor. HandlerInterceptor can be used to avoid repetitive handler code.
We can use HandlerInterceptor for different purposes like authorization checks, locale checks, logging, creating common application parameters etc.
HandlerInterceptor works similar to the servlet filter. But in some cases filters are more powerful than HandlerInterceptor.
In Spring-MVC the HandlerInterceptor is configured in spring application context xml file or by Java configuration.
HandlerInterceptor has three methods.
preHandle( ) : It is executed before actual handler is executed.
postHandle( ) : It is executed after handler is executed.
afterCompletion( ) : It is executed after the complete request is finished.
For more details, you can use an example from the below link
https://www.tuturself.com/posts/view?menuId=3&postId=1071
You can get the entire sample project which can help you with the setup at
https://github.com/ninja-panda

To get the request url you can do the following:
#RequestMapping(value = "/ui/report/win", method = RequestMethod.GET)
public String winReport(HttpServletRequest request){
String request = request.getRequestURI();
// do somehting here
return "win_report"
}
Spring will automatically inject the HttpServletRequest.
Update:
If your want get the urls for all of your methods in your controller, you can go with RequestMappingHandlerMapping:
private final RequestMappingHandlerMapping handlerMapping;
#Autowired
public YourController(RequestMappingHandlerMapping handlerMapping) {
this.handlerMapping = handlerMapping;
}
With handlerMapping.getHandlerMethods(), you can access all mappings decleared in your controller. With reflection and getMappingAnnotation, you can then read the value of each RequestMapping annotation.

You can try the getServletPath() like following:
#RequestMapping(value = "/ui/report/win", method = RequestMethod.GET)
public String winReport(HttpServletRequest request){
String mapping = request.getServletPath();
// do somehting here
System.out.println(mapping); // Will print /ui/report/win
return "win_report"
}

Spring Cloud Zuul: RedirectView redirecting to service and not gateway

I'm a bit new to microservices and Spring. I have Spring Cloud microservices (ports: 8xxx-8xxx) with a Zuul gateway running on port 9000. There's a method inside a controller on a UI service which should do a login and then return to a index.html page:
#RequestMapping(value="/do-login", method = RequestMethod.POST)
public RedirectView doLogin (#ModelAttribute("authEntity") final AuthEntity authEntity, final Model model) {
model.addAttribute(VERSION, applicationVersion);
model.addAttribute("authEntity", new AuthEntity());
authenticatedStatus = true;
model.addAttribute(AUTHENTICATED, authenticatedStatus);
return new RedirectView("index");
}
The problem is that when above method completes it returns an url of the microservice itself localhost:8888/index but not localhost:9000/services/ui/.
If I use a simpler method:
#RequestMapping(value="/do-login", method = RequestMethod.POST)
public String doLogin (#ModelAttribute("authEntity") final AuthEntity authEntity, final Model model) {
model.addAttribute(VERSION, applicationVersion);
model.addAttribute("authEntity", new AuthEntity());
authenticatedStatus = true;
model.addAttribute(AUTHENTICATED, authenticatedStatus);
return "index";
}
This returns correctly an url of gateway localhost:9000/services/ui/do-login but with a /do-login which I do not need.
Maybe I can get rid of /do-login/ part of url? Or maybe there is a solution for the incorrect redirect?
Thanks in advance!

If you use relative path like in return "index"; the result of the POST request sent to http://localhost:9000/services/ui/do-login will include URLs to http://localhost:9000/... unless coded otherwise in the jsp / freemarker / thymeleaf file.
If you want to get rid of the do-login, you would need to implement what's called a Redirect After Post (or redirect after form submit) approach so that a page refresh doesn't resubmit the form. If you take this approach, which seem what you were doing when using: return new RedirectView("index");, I can think of a couple ways of fixing the URL and set it to the proxy host.
1) http://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/servlet/view/RedirectView.html, there are a couple of constructors that takes a host parameter, you would need to inject the proxy host in the controller class and most-likely in every controller class that implements Redirect After Post.
2) http://tuckey.org/urlrewrite/, include UrlRewriteFilter and configure rules to rewrite from webapp host to proxy host when webapp http status code response is 302. With this approach it would only be once rule and no need to inject proxy host to controller classes or change the return new RedirectView("index");`
3) Maybe this rewriting is implemented in Zuul and you don't need include and configure UrlRewriteFilter as suggested in 2).
As a side note, I have configured Nginx's proxy_pass to a Java webapps (where I implemented Redirect After Post) in the past and I don't recall having this issue. Will have to take a look at both UrlRewriteFilter and Nginx config files to expand on this.

I found that this (thanks to answer in here: Spring redirect url issue when behind Zuul proxy) seems to work as required (but is considered a 'workaround'):
#RequestMapping(value="/do-login", method = RequestMethod.POST)
public void doLogin (#ModelAttribute("authEntity") final AuthEntity authEntity,
final Model model,
HttpServletResponse servletResponse) throws IOException {
...
String rUrl = ServletUriComponentsBuilder.fromCurrentContextPath().path("/").build().toUriString();
servletResponse.sendRedirect(rUrl);
}

Preserving model state with Post/Redirect/Get pattern and URL rewriting

First of all, I know that there are similar questions regarding "Preserving model state with Post/Redirect/Get pattern", but none of these have my very specific problem:
background:
My Code is working in an enterprise CMS software which does a lot of things. One of them is URL rewriting: Whenever I generate Links to my controller, dependending on the environment, the links are shortened - That's a SEO thing and can't be discussed.
I.e. if my Controller URL is /webapp/servlet/myController/doSomething, the generated URL will be /myController/doSomething. There's some LinkProcessing functionality that we have to use.
An apache rewrite rule will then expand this short url to /webapp/servlet/myController/doSomething when the apache uses mod_rewrite to call the corresponsing code on the tomcat:
RewriteCond %{REQUEST_URI} ^/myController/(.*)
RewriteRule ^/myController/(.*) /webapp/servlet/myController/$1 [PT,L]
Problem:
I'm trying to implement the Post/Redirect/Get pattern using Spring 3.1.2. I'm generating a form and POST it to the Controller, which validated and makes a redirect to either the success or error page using GET (Post/Redirect/Get pattern).
(highly simplified) Code:
#RequestMapping()
public class MyController {
#RequestMapping(value = "/doDispatch", method = RequestMethod.POST)
public RedirectView handleDispatch(RedirectAttributes redirectAttributes,
#Validated #ModelAttribute FormBean formBean,
BindingResult binding) {
if (binding.hasErrors()) {
redirectAttributes.addFlashAttribute(formBean);
redirectAttributes.addFlashAttribute(BindingResult.MODEL_KEY_PREFIX+"formBean", binding);
return new RedirectView(generateLink("/error"));
} else {
redirectAttributes.addFlashAttribute(formBean);
redirectAttributes.addFlashAttribute(BindingResult.MODEL_KEY_PREFIX+"formBean", binding);
return new RedirectView(generateLink("/success"));
}
}
#RequestMapping(value = "/success")
public ModelAndView handleSuccess(#ModelAttribute FormBean formBean) {
// do stuff (save things in the DB)
// ...
final ModelAndView modelAndView = createModelAndView(formBean);
modelAndView.addObject("success", true);
return modelAndView;
}
#RequestMapping(value = "/error")
public ModelAndView handleError(#Validated #ModelAttribute FormBean formBean,
BindingResult binding) {
final ModelAndView modelAndView = createModelAndView(formBean);
modelAndView.addObject("binding", binding);
modelAndView.addObject("formBean", formBean);
return modelAndView;
}
}
The problem ist that this generateLink() method will either generate links starting with /webapp/servlet or not - depending on the environment/success. And that's how this whole Enterprice CMS thing works. (that's the part which cannot be discussed)
Spring Flash-Attributes on the other hand work hand in hand with the URLs that are returned and store the URL as part of the FlashMap:
Quote from http://docs.spring.io/spring/docs/current/spring-framework-reference/html/mvc.html#mvc-flash-attributes :
To reduce the possibility of such issues, RedirectView automatically "stamps" FlashMap instances with the path and query parameters of the target redirect URL. In turn the default FlashMapManager matches that information to incoming requests when looking up the "input" FlashMap.
Since the next request (let's say I've had an error and returned "/myController/error") will be expanded to /webapp/servlet/myController/error, the FlashMap will not apply to this request, since the URLs do not match.
The code that is responsible is this here (AbstractFlashMapManager.java:157 ff):
protected boolean isFlashMapForRequest(FlashMap flashMap, HttpServletRequest request) {
if (flashMap.getTargetRequestPath() != null) {
String requestUri = this.urlPathHelper.getOriginatingRequestUri(request);
if (!requestUri.equals(flashMap.getTargetRequestPath())
&& !requestUri.equals(flashMap.getTargetRequestPath() + "/")) {
return false;
}
}
// ...
}
Question:
Do you know a way how I can still generate short URLs on the one hand, but pass the FlashAttributes to the following GET request?
Best regards and thanks for your help in advance,
Alexander

The best solution I've found so far is using an Interceptor that updates the targetRequestPath by prefixing /<webappPath>/<servletPath> to those FlashMaps from RequestContextUtils.getOutputFlashMap(request) that are missing this information. BTW: this can only be done in the afterCompletion method, because otherwise the targetRequestPath won't be set at all, when using a RedirectView.
Any other, better solutions?

In spring mvc how to get the context path in controller

I need application context path in controller, I tried the below code its throwing NULLPOINTER EXCEPTION.
HttpServletRequest request;
String Path = request.getContextPath();
Please help me
Thanks

Variable request is declared, but is not
initialized. No wonder you get a NullPointerException.
Look at documentation to access different request related data.
After you read that, and are sure you want to tie your code to native Servlet API, try this:
#Controller
class MyController {
#RequestMapping
public void handleMe(HttpServletRequest request) {
String path = request.getContextPath();
}
}