Question

我已尝试在what is the right way to handle errors in spring-webflux中建议的所有3个解决方案，但WebExceptionHandler未被调用。我正在使用Spring Boot 2.0.0.M7。 Github回购here

@Configuration
class RoutesConfiguration {

  @Autowired
  private lateinit var testService: TestService

  @Autowired
  private lateinit var globalErrorHandler: GlobalErrorHandler

  @Bean
  fun routerFunction():

    RouterFunction<ServerResponse> = router {
    ("/test").nest {

      GET("/") {
        ServerResponse.ok().body(testService.test())
      }
    }
  }


} 


@Component
class GlobalErrorHandler() : WebExceptionHandler {

  companion object {
    private val log = LoggerFactory.getLogger(GlobalErrorHandler::class.java)
  }

  override fun handle(exchange: ServerWebExchange?, ex: Throwable?): Mono<Void> {

    log.info("inside handle")

    /* Handle different exceptions here */
    when(ex!!) {
      is ClientException -> exchange!!.response.statusCode = HttpStatus.BAD_REQUEST
      is Exception -> exchange!!.response.statusCode = HttpStatus.INTERNAL_SERVER_ERROR
    }

    return Mono.empty()
  }
}

更新

当我将Spring Boot版本更改为2.0.0.M2时，WebExceptionHandler将被调用。我需要为2.0.0.M7做些什么吗？

SOLUTION：

根据Brian的建议，它可以作为

@Bean
@Order(-2)
fun globalErrorHandler() = GlobalErrorHandler()

Answer 1

您可以提供自己的WebExceptionHandler，但是您必须相对于其他人订购，否则他们可能会在您有机会尝试之前处理错误。

Spring Boot提供的DefaultErrorWebExceptionHandler错误处理（see reference documentation）在-1订购
Spring Framework提供的ResponseStatusExceptionHandler是0

因此，您可以在错误处理组件上添加@Order(-2)，以便在现有组件之前对其进行排序。

Answer 2

错误响应应具有标准有效内容信息。这可以通过扩展AbstractErrorWebExceptionHandler

来完成

ErrorResponse ：数据类

data class ErrorResponse(
    val timestamp: String,
    val path: String,
    val status: Int,
    val error: String,
    val message: String
)

ServerResponseBuilder ：构建错误响应的2种不同方法

默认：处理标准错误

webClient ：处理webClient例外（WebClientResponseException），不适用于此案例

class ServerResponseBuilder(
        private val request: ServerRequest, 
        private val status: HttpStatus) {

    fun default(): Mono<ServerResponse> =
        ServerResponse
                .status(status)
                .body(BodyInserters.fromObject(ErrorResponse(
                        Date().format(),
                        request.path(),
                        status.value(),
                        status.name,
                        status.reasonPhrase)))

    fun webClient(e: WebClientResponseException): Mono<ServerResponse> =
        ServerResponse
                .status(status)
                .body(BodyInserters.fromObject(ErrorResponse(
                        Date().format(),
                        request.path(),
                        e.statusCode.value(),
                        e.message.toString(),
                        e.responseBodyAsString)))
}

GlobalErrorHandlerConfiguration ：错误处理程序

@Configuration
@Order(-2)
class GlobalErrorHandlerConfiguration @Autowired constructor(
        errorAttributes: ErrorAttributes,
        resourceProperties: ResourceProperties,
        applicationContext: ApplicationContext,
        viewResolversProvider: ObjectProvider<List<ViewResolver>>,
        serverCodecConfigurer: ServerCodecConfigurer) :
        AbstractErrorWebExceptionHandler(
                errorAttributes,
                resourceProperties,
                applicationContext
        ) {

    init {
        setViewResolvers(viewResolversProvider.getIfAvailable { emptyList() })
        setMessageWriters(serverCodecConfigurer.writers)
        setMessageReaders(serverCodecConfigurer.readers)
    }

    override fun getRoutingFunction(errorAttributes: ErrorAttributes?): RouterFunction<ServerResponse> = 
        RouterFunctions.route(RequestPredicates.all(), HandlerFunction<ServerResponse> { response(it, errorAttributes) })

    private fun response(request: ServerRequest, errorAttributes: ErrorAttributes?): Mono<ServerResponse> =
        ServerResponseBuilder(request, status(request, errorAttributes)).default()

    private fun status(request: ServerRequest, errorAttributes: ErrorAttributes?) =
        HttpStatus.valueOf(errorAttributesMap(request, errorAttributes)["status"] as Int)

    private fun errorAttributesMap(request: ServerRequest, errorAttributes: ErrorAttributes?) =
        errorAttributes!!.getErrorAttributes(request, false)
}

Spring 5 Reactive - 没有调用WebExceptionHandler

2 个答案: