refactor: Validation 예외 전역 처리 추가

Author: larama-C

src/main/java/com/back/web7_9_codecrete_be/global/error/handler/GlobalExceptionHandler.java

@@ -1,14 +1,13 @@
 package com.back.web7_9_codecrete_be.global.error.handler;
 
-import org.springframework.http.ResponseEntity;
-import org.springframework.web.bind.annotation.ExceptionHandler;
-import org.springframework.web.bind.annotation.RestControllerAdvice;
-
 import com.back.web7_9_codecrete_be.global.error.exception.BusinessException;
 import com.back.web7_9_codecrete_be.global.error.util.ErrorResponse;
 import com.back.web7_9_codecrete_be.global.rsData.RsData;
-
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
 
 @Slf4j
 @RestControllerAdvice
@@ -20,4 +19,24 @@ public ResponseEntity<RsData<Void>> handleBusinessException(BusinessException ex
 		return ErrorResponse.build(ex.getErrorCode());
 	}
 
+    // @Valid 검증 실패 처리
+    @ExceptionHandler(MethodArgumentNotValidException.class)
+    public ResponseEntity<RsData<Void>> handleValidationException(
+            MethodArgumentNotValidException ex
+    ) {
+        String message = ex.getBindingResult()
+                .getFieldErrors()
+                .stream()
+                .findFirst()
+                .map(error -> error.getDefaultMessage())
+                .orElse("입력값이 올바르지 않습니다.");
+
+        return ResponseEntity
+                .badRequest()
+                .body(new RsData<>(
+                        400,
+                        "VALIDATION_ERROR",
+                        message
+                ));
+    }
 }