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Merged
polyglot-k merged 1 commit into from
Aug 11, 2025
Merged

feat: implement saveOrGetUser method to streamline user creation and … #311

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2 changes: 1 addition & 1 deletion src/main/java/life/mosu/mosuserver/application/application/ApplicationService.java
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Original file line number Diff line number Diff line change
Expand Up @@ -61,7 +61,7 @@ public CreateApplicationResponse apply(Long userId, ApplicationRequest request)

@Transactional
public CreateApplicationResponse applyByGuest(ApplicationGuestRequest request) {
Long userId = userService.saveUser(request.toUserJpaEntity());
Long userId = userService.saveOrGetUser(request.toUserJpaEntity());
CreateApplicationResponse response = handleApplication(
userId,
List.of(request.examApplication().examId()),
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16 changes: 10 additions & 6 deletions src/main/java/life/mosu/mosuserver/application/user/UserService.java
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Original file line number Diff line number Diff line change
Expand Up @@ -37,12 +37,16 @@ public void syncUserInfoFromProfile(UserJpaEntity user, ProfileJpaEntity profile
}
}

public Long saveUser(UserJpaEntity user) {
Long userId = userJpaRepository.save(user).getId();
if (userId == null) {
throw new CustomRuntimeException(ErrorCode.USER_SAVE_FAILED);
}
return userId;
public Long saveOrGetUser(UserJpaEntity user) {
return userJpaRepository.findByPhoneNumber(user.getPhoneNumber())
.map(UserJpaEntity::getId)
.orElseGet(() -> {
Long userId = userJpaRepository.save(user).getId();
if (userId == null) {
throw new CustomRuntimeException(ErrorCode.USER_SAVE_FAILED);
}
return userId;
});
}
Comment on lines +40 to 50
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@gemini-code-assist gemini-code-assist bot Aug 11, 2025

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high

The current implementation of saveOrGetUser is vulnerable to a race condition. If two concurrent requests attempt to create a user with the same phone number, both might find that the user doesn't exist and then both attempt to save a new user. This will lead to one of the transactions failing with a unique constraint violation (e.g., DataIntegrityViolationException).

To handle this, you can catch the DataIntegrityViolationException and re-query for the user, which should exist at that point. This is a common pattern for handling get-or-create scenarios under concurrency.

Additionally, I recommend annotating the method with @Transactional to ensure it always runs within a transaction, providing predictable behavior. You'll need to import org.springframework.transaction.annotation.Transactional and org.springframework.dao.DataIntegrityViolationException.

Suggested change
public Long saveOrGetUser(UserJpaEntity user) {
return userJpaRepository.findByPhoneNumber(user.getPhoneNumber())
.map(UserJpaEntity::getId)
.orElseGet(() -> {
Long userId = userJpaRepository.save(user).getId();
if (userId == null) {
throw new CustomRuntimeException(ErrorCode.USER_SAVE_FAILED);
}
return userId;
});
}
@Transactional
public Long saveOrGetUser(UserJpaEntity user) {
return userJpaRepository.findByPhoneNumber(user.getPhoneNumber())
.map(UserJpaEntity::getId)
.orElseGet(() -> {
try {
Long userId = userJpaRepository.save(user).getId();
if (userId == null) {
throw new CustomRuntimeException(ErrorCode.USER_SAVE_FAILED);
}
return userId;
} catch (org.springframework.dao.DataIntegrityViolationException e) {
// Race condition: another transaction might have created the user. Re-fetch.
return userJpaRepository.findByPhoneNumber(user.getPhoneNumber())
.map(UserJpaEntity::getId)
.orElseThrow(() -> new CustomRuntimeException(ErrorCode.USER_SAVE_FAILED));
}
});
}


public UserInfoResponse getUserInfo(Long userId) {
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