FEATURE: implementation custom error handler #4

src/main/kotlin/eom/improve/kafkaboot/common/ErrorResponse.kt

@@ -0,0 +1,21 @@
+package eom.improve.kafkaboot.common
+
+import com.fasterxml.jackson.annotation.JsonProperty
+import org.springframework.http.HttpStatus
+import java.time.ZonedDateTime
+
+data class ErrorResponse(
+    @get:JsonProperty("path") val path: String,
+    @get:JsonProperty("status") val status: HttpStatus,
+    @get:JsonProperty("message") val message: String,
+    @get:JsonProperty("error") val error: String = status.reasonPhrase,
+    @get:JsonProperty("requestId") val requestId: String = path.substringAfterLast("/"),
+    @get:JsonProperty("timestamp") val timestamp: ZonedDateTime= ZonedDateTime.now()
+) {
+    constructor() : this(
+        path = "",
+        status = HttpStatus.INTERNAL_SERVER_ERROR,
+        message = HttpStatus.INTERNAL_SERVER_ERROR.name,
+        timestamp = ZonedDateTime.now()
+    )
+}

src/main/kotlin/eom/improve/kafkaboot/controller/GlobalExceptionHandler.kt

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+package eom.improve.kafkaboot.controller
+
+import eom.improve.kafkaboot.common.ErrorResponse
+import eom.improve.kafkaboot.exception.BadRequestException
+import org.springframework.http.HttpStatus
+import org.springframework.web.bind.annotation.ExceptionHandler
+import org.springframework.web.bind.annotation.ResponseBody
+import org.springframework.web.bind.annotation.RestControllerAdvice
+import org.springframework.web.bind.support.WebExchangeBindException
+import org.springframework.web.server.ServerWebExchange
+import reactor.core.publisher.Flux
+import reactor.core.publisher.Mono
+import reactor.kotlin.core.publisher.toMono
+import java.util.stream.Collectors
+
+@RestControllerAdvice
+class GlobalExceptionHandler {
+
+    @ExceptionHandler(WebExchangeBindException::class)
+    @ResponseBody
+    fun handleBadRequestException(exchange: ServerWebExchange, ex: WebExchangeBindException): Mono<ErrorResponse> {
+        var defaultMsg: String = ex.bindingResult.fieldErrors.stream()
+            .map { fieldError -> fieldError.defaultMessage }
+            .collect(Collectors.joining(", "))
+
+        return ErrorResponse(
+            path = exchange.request.path.toString(),
+            status = HttpStatus.BAD_REQUEST,
+            message = defaultMsg,
+            error = HttpStatus.BAD_REQUEST.reasonPhrase,
+            requestId = exchange.request.id
+        ).toMono()
+    }
+    // need to implement error logging publish to kafka
+}

src/main/kotlin/eom/improve/kafkaboot/exception/BadRequestException.kt

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+package eom.improve.kafkaboot.exception
+
+class BadRequestException : RuntimeException {
+    constructor(message : String) : super(message)
+    constructor(message : String, cause : Throwable) : super(message, cause)
+    constructor(cause : Throwable) : super(cause)
+}