[BE] refactor: 서비스 리팩터링

backend/src/main/java/reviewme/review/domain/Review.java

@@ -13,6 +13,9 @@
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 import lombok.AccessLevel;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -55,6 +58,20 @@ public Review(long templateId, long reviewGroupId,
         this.createdAt = LocalDateTime.now();
     }
 
+    public Set<Long> getAllQuestionIdsFromAnswers() {
+        return Stream.concat(
+                textAnswers.stream().map(TextAnswer::getQuestionId),
+                checkboxAnswers.stream().map(CheckboxAnswer::getQuestionId)
+        ).collect(Collectors.toSet());
+    }
+
+    public Set<Long> getAllCheckBoxOptionIds() {
+        return checkboxAnswers.stream()
+                .flatMap(answer -> answer.getSelectedOptionIds().stream())
+                .map(CheckBoxAnswerSelectedOption::getSelectedOptionId)
+                .collect(Collectors.toSet());
+    }
+
     public LocalDate getCreatedDate() {
         return createdAt.toLocalDate();
     }

backend/src/main/java/reviewme/review/service/ReviewRegisterService.java

@@ -0,0 +1,32 @@
+package reviewme.review.service;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import reviewme.review.domain.Review;
+import reviewme.review.repository.ReviewRepository;
+import reviewme.review.service.dto.request.CreateReviewRequest;
+import reviewme.review.service.module.CheckBoxAnswerValidator;
+import reviewme.review.service.module.ReviewMapper;
+import reviewme.review.service.module.ReviewValidator;
+import reviewme.review.service.module.TextAnswerValidator;
+
+@Service
+@RequiredArgsConstructor
+public class ReviewRegisterService {
+
+    private final ReviewMapper reviewMapper;
+    private final ReviewValidator reviewValidator;
+    private final TextAnswerValidator textAnswerValidator;
+    private final CheckBoxAnswerValidator checkBoxAnswerValidator;
+
+    private final ReviewRepository reviewRepository;
+
+    @Transactional
+    public long registerReview(CreateReviewRequest request) {
+        Review review = reviewMapper.mapToReview(request, textAnswerValidator, checkBoxAnswerValidator);
+        reviewValidator.validate(review);
+        Review registeredReview = reviewRepository.save(review);
+        return registeredReview.getId();
+    }
+}