Spring 404 on endpoint at root context path

I'm switching my apps from spring mvc to use with spring boot. To do that, i've build small projects spring mvc and spring-boot like examples.

I found what seems to be a bug with endpoint path at root context path of dispatcher. Defining a simple RestController without RequestMapping. When i call request on that, there is a 404 response

POST http://localhost:8080/api HTTP/1.1 404

But, when i add "/" at the end of request, all is good

POST http://localhost:8080/api/ HTTP/1.1 204

The good request is "POST http://localhost:8080/api", isn't it ?

All others requests are ok (like /api/sub or /api/two/other)

when debugging this problem, i realized that the problem could be

https://github.com/spring-projects/spring-framework/blob/7c982511426eebea3d34730ab128bb39a55a9de6/spring-web/src/main/java/org/springframework/web/util/UrlPathHelper.java#L236

if replace this line with if (null != rest) { all request are now good

Or here : defaut path must be "/" not "" ? https://github.com/spring-projects/spring-framework/blob/7c982511426eebea3d34730ab128bb39a55a9de6/spring-web/src/main/java/org/springframework/web/util/UrlPathHelper.java#L358

To reproduce : - spring mvc - spring-boot

Examples are with multiple dispatcher, but problem occurred with one dispatcher

spring 5.2.10.RELEASE spring boot 2.3.5.RELEASE

Comment From: dPechman42

I made these changes to your code and it is working now AppController.java

  @PostMapping("/api")
  public ResponseEntity<Void> postIt(final HttpServletRequest request) {
    return ResponseEntity.noContent().build();
  }

  @GetMapping("/api")
  public ResponseEntity<Void> getIt(final HttpServletRequest request) {
    return ResponseEntity.noContent().build();
  }

  @PostMapping("/api/{id}")
  public ResponseEntity<Void> post(final HttpServletRequest request) {
    return ResponseEntity.noContent().build();
  }

  @GetMapping("/api/{id}")
  public ResponseEntity<Void> get(final HttpServletRequest request) {
    return ResponseEntity.noContent().build();
  }

ApiInitializer.java

  protected String[] getServletMappings() {
    return new String[]{"/*"};
  }

OtherController.java

  @PostMapping("/other")
  public ResponseEntity<Void> postOther(final HttpServletRequest request) {
    return ResponseEntity.noContent().build();
  }

  @GetMapping("/other")
  public ResponseEntity<Void> getOther(final HttpServletRequest request) {
    return ResponseEntity.noContent().build();
  }

Comment From: Fyro-Ing

Yes "of course", but i don't want context in "@***Mapping"

On my app, i use same Controller for 2 context (/api & /backoffice as example) but security & others applied on that context are different. All is ok, only endpoint on root context path are ko

Comment From: bclozel

Sorry for getting back to you after so long. The sample application has an invalid setup: it's got multiple @SpringBootApplication classes and multiple DispatcherServlet registrations with the same configurations. It's not clear what you're trying to achieve and this point and this does not look like a Spring Framework issue.

Comment From: Fyro-Ing

@bclozel i linked on the line caused bug and this is a spring issue

if (!"".equals(rest)) {

this not the same configuration on sample, context path is different I try to reuse same controller, on multiple context, to apply business from context