[BE/#29] Feat : 전역 에러 핸들러 추가

- GlobalExceptionHandler

BE/src/main/java/com/codesquad/issuetracker/ragdoll/exception/GlobalExceptionHandler.java

@@ -0,0 +1,19 @@
+package com.codesquad.issuetracker.ragdoll.exception;
+
+import com.codesquad.issuetracker.ragdoll.commonconstant.ErrorMessages;
+import com.codesquad.issuetracker.ragdoll.response.ApiResponse;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.ResponseBody;
+
+@ControllerAdvice
+public class GlobalExceptionHandler {
+
+    @ExceptionHandler(UserUnauthorizedException.class)
+    @ResponseBody
+    public ResponseEntity<ApiResponse<String>> handleUserUnauthorizeedException(UserUnauthorizedException userUnauthorizedException) {
+        return new ResponseEntity(ApiResponse.UNAUTHORIZED(ErrorMessages.USER_UNAUTHORIZED), HttpStatus.UNAUTHORIZED);
+    }
+}