Spring Boot Application scenarios to Start with WebFlux and Custom scenarios Handling
I'm getting frustrated with I've been banging my head against this for hours. I'm working on a Spring Boot application using WebFlux for reactive programming, and I have implemented a custom behavior handling mechanism using `@ControllerAdvice`. However, when I run the application, it throws a `WebExchangeBindException` on certain inputs, but instead of returning my custom behavior response, it crashes with the following stack trace: ``` org.springframework.web.server.ResponseStatusException: 400 BAD_REQUEST at org.springframework.web.server.ServerWebExchange.setStatusCode(ServerWebExchange.java:141) at org.springframework.web.reactive.function.server.RouterFunctions$ToHttpHandlerAdapter.handle(RouterFunctions.java:280) at org.springframework.web.reactive.function.server.RouterFunctions$ToHttpHandlerAdapter.handle(RouterFunctions.java:200) ... 65 more ``` I've tried adding a `@ExceptionHandler` method in my `@ControllerAdvice`, but it seems like the exception is being thrown before it reaches my handler. Here's how I have configured my `ControllerAdvice`: ```java @ControllerAdvice public class GlobalExceptionHandler { @ExceptionHandler(WebExchangeBindException.class) public Mono<ResponseEntity<String>> handleValidationExceptions(WebExchangeBindException ex) { return Mono.just(ResponseEntity.badRequest().body("Validation failed: " + ex.getMessage())); } } ``` The scenario seems to arise particularly with a POST request to my endpoint that looks like this: ```java @PostMapping("/api/data") public Mono<ResponseEntity<DataResponse>> createData(@RequestBody DataRequest request) { // Some processing logic } ``` What I've observed is that the behavior handling works perfectly for other exceptions, but it fails for validation exceptions caused by `@Valid` annotations in my `DataRequest` object. The `DataRequest` class looks like this: ```java public class DataRequest { @NotNull(message = "Field want to be null") private String field; // getters and setters } ``` I've also verified that I'm using Spring Boot version 2.6.0 and the corresponding WebFlux dependencies. Has anyone faced a similar scenario or can provide insight into what might be causing my custom behavior handler to be bypassed? My development environment is Linux. What am I doing wrong? I'm working in a Linux environment. Any examples would be super helpful.