[KAN-8] global exception 처리 작업 (#5)

* [KAN-8] global exception 처리 작업

* [KAN-8] global exception 처리 작업 - lint

src/main/kotlin/com/restaurant/be/common/exception/GlobalException.kt

@@ -0,0 +1,18 @@
+package com.restaurant.be.common.exception
+
+import org.springframework.http.HttpStatus
+import org.springframework.web.server.ResponseStatusException
+
+open class GlobalException : ResponseStatusException {
+    constructor(status: HttpStatus?) : super(status!!)
+    constructor(status: HttpStatus?, reason: String?) : super(status!!, reason)
+    constructor(status: HttpStatus?, reason: String?, cause: Throwable?) : super(
+        status!!,
+        reason,
+        cause
+    )
+
+    companion object {
+        private const val serialVersionUID = -1L
+    }
+}

src/main/kotlin/com/restaurant/be/common/exception/GlobalExceptionHandler.kt

@@ -0,0 +1,83 @@
+package com.restaurant.be.common.exception
+
+import com.fasterxml.jackson.databind.exc.MismatchedInputException
+import com.fasterxml.jackson.module.kotlin.MissingKotlinParameterException
+import com.restaurant.be.common.response.CommonResponse
+import com.restaurant.be.common.response.Error
+import com.restaurant.be.common.response.ErrorCode
+import org.springframework.http.HttpStatus
+import org.springframework.http.ResponseEntity
+import org.springframework.validation.FieldError
+import org.springframework.web.bind.annotation.ExceptionHandler
+import org.springframework.web.bind.annotation.ResponseStatus
+import org.springframework.web.bind.annotation.RestControllerAdvice
+import org.springframework.web.bind.support.WebExchangeBindException
+import org.springframework.web.server.ServerWebExchange
+import org.springframework.web.server.ServerWebInputException
+
+@RestControllerAdvice
+class GlobalExceptionHandler {
+
+    @ExceptionHandler(ServerException::class)
+    fun handleServerException(
+        ex: ServerException,
+        exchange: ServerWebExchange
+    ): ResponseEntity<Any> {
+        val response = CommonResponse.fail(ex.message, ex.javaClass.simpleName)
+        return ResponseEntity(response, null, ex.code)
+    }
+
+    @ResponseStatus(HttpStatus.BAD_REQUEST)
+    @ExceptionHandler(value = [ServerWebInputException::class])
+    fun methodArgumentNotValidException(
+        e: ServerWebInputException,
+        exchange: ServerWebExchange
+    ): CommonResponse<String?> {
+        val data =
+            if (e.cause?.cause is MissingKotlinParameterException) {
+                val param = (e.cause?.cause as MissingKotlinParameterException).parameter.name
+                "항목 ${param}을 확인해주세요"
+            } else if (e.cause?.cause is MismatchedInputException) {
+                e.message
+            } else {
+                null
+            }
+
+        val errorResponse = CommonResponse.fail(data, ErrorCode.COMMON_NULL_PARAMETER)
+        return errorResponse
+    }
+
+    @ResponseStatus(HttpStatus.BAD_REQUEST)
+    @ExceptionHandler(value = [WebExchangeBindException::class])
+    fun methodArgumentNotValidException(
+        e: WebExchangeBindException,
+        exchange: ServerWebExchange
+    ): CommonResponse<String> {
+        val errors = mutableListOf<Error>()
+        e.allErrors.forEach {
+            val error =
+                Error(
+                    field = (it as FieldError).field,
+                    message = it.defaultMessage,
+                    value = it.rejectedValue
+                )
+            errors.add(error)
+        }
+
+        val errorResponse =
+            CommonResponse
+                .fail(errors.toString(), ErrorCode.COMMON_INVALID_PARAMETER)
+
+        return errorResponse
+    }
+
+    @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
+    @ExceptionHandler(value = [Exception::class])
+    fun exception(
+        e: Exception,
+        exchange: ServerWebExchange
+    ): CommonResponse<String?> {
+        val errorResponse = CommonResponse.fail(e.message, e::class.java.simpleName)
+        return errorResponse
+    }
+}

src/main/kotlin/com/restaurant/be/common/exception/ServerException.kt

@@ -0,0 +1,6 @@
+package com.restaurant.be.common.exception
+
+sealed class ServerException(
+    val code: Int,
+    override val message: String
+) : RuntimeException(message)

src/main/kotlin/com/restaurant/be/common/response/CommonResponse.kt

@@ -0,0 +1,80 @@
+package com.restaurant.be.common.response
+
+data class CommonResponse<T>(
+    val result: Result,
+    val data: T?,
+    val message: String,
+    val errorCode: String?
+) {
+
+    companion object {
+        // status 200 + success (message가 있을 경우)
+        fun <T> success(data: T, message: String): CommonResponse<T> {
+            return CommonResponse(
+                result = Result.SUCCESS,
+                data = data,
+                message = message,
+                errorCode = null
+            )
+        }
+
+        // status 200 + success (message가 없을 경우)
+        fun <T> success(data: T): CommonResponse<T> {
+            return CommonResponse(
+                result = Result.SUCCESS,
+                data = data,
+                message = "",
+                errorCode = null
+            )
+        }
+
+        // status 200 + success (data가 없을 경우)
+        fun <T> success(): CommonResponse<T> {
+            return CommonResponse(
+                result = Result.SUCCESS,
+                data = null,
+                message = "",
+                errorCode = null
+            )
+        }
+
+        // status 200 + fail
+        fun <T> fail(data: T, message: String): CommonResponse<T> {
+            return CommonResponse(
+                result = Result.FAIL,
+                data = data,
+                message = message,
+                errorCode = null
+            )
+        }
+
+        fun <T> fail(data: T, errorCode: ErrorCode): CommonResponse<T> {
+            return CommonResponse(
+                result = Result.FAIL,
+                data = data,
+                message = errorCode.errorMsg,
+                errorCode = errorCode.name
+            )
+        }
+
+        fun fail(message: String, exceptionName: String): CommonResponse<Nothing> {
+            return CommonResponse(
+                result = Result.FAIL,
+                data = null,
+                message = message,
+                errorCode = exceptionName
+            )
+        }
+    }
+
+    enum class Result {
+        SUCCESS,
+        FAIL
+    }
+}
+
+data class Error(
+    val field: String? = null,
+    val message: String? = null,
+    val value: Any? = null
+)

src/main/kotlin/com/restaurant/be/common/response/ErrorCode.kt

@@ -0,0 +1,18 @@
+package com.restaurant.be.common.response
+
+enum class ErrorCode(
+    val errorMsg: String
+) {
+    // 500
+    COMMON_SYSTEM_ERROR("일시적인 오류가 발생했습니다. 잠시 후 다시 시도해주세요."),
+
+    // 400
+    COMMON_NULL_PARAMETER("빠뜨린 값이 없는지 확인 해주세요."),
+    COMMON_INVALID_PARAMETER("요청한 값이 올바르지 않습니다.")
+
+    ;
+
+    fun getErrorMsg(vararg arg: Any?): String {
+        return String.format(errorMsg, *arg)
+    }
+}