Concurrent transaction issue in keycloak user attribute (java spring boot) - spring-boot

Question

I managed our customer's point as keycloak user attribute.
I set 'point' as user attribute, and I handled it with keycloak api in Java Spring boot.
So, flow of update point is..
point = getPointByUserEmail(userEmail); // get point to update.
point -= 10; // minus point
updatePointByUserEmail(userEmail, point); // update point
public Long getPointByUserEmail(String userEmail) {
UserRepresentation userRepresentation = usersResource.search(userEmail, true).get(0);
Map<String, List<String>> attributes = userRepresentation.getAttributes();
if (attributes == null || attributes.get("point") == null)
return null;
return Long.parseLong(attributes.get("point").get(0));
}
public void updatePointByUserEmail(String userEmail, Long point) {
UserRepresentation userRepresentation = usersResource.search(userEmail, true).get(0);
UserResource userResource = usersResource.get(userRepresentation.getId());
Map<String, List<String>> attributes = userRepresentation.getAttributes();
attributes.put("point", Arrays.asList(point.toString()));
userRepresentation.setAttributes(attributes);
userResource.update(userRepresentation);
}
It works well.
But my problem is when user requests simultaneously at almost same time to update point,
It doesn't work well.
For example, there are 2 requests at once. (initial point = 100, minus point per request = 10)
I expected it would be 80 point, because 100 - (10 * 2) = 80
But it was 90 point.
So I think I need to set isolation level to transaction in point.
In JPA, there is #Lock annotation... but,, how can I do it in keycloak ?
Is there any way that I can set isolation level in keycloak api so that my function will work well ?
This is code when I handle point,
public class someController {
public ResponseEntity<String> methodToHandleRequest(#RequestBody Dto param, HttpServletRequest request) {
...
Long point = null;
try {
point = userAttributesService.getPoint();
if (point == null)
throw new NullPointerException();
} catch (Exception e) {
e.printStackTrace();
return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body("error");
}
if (point < 10)
return ResponseEntity.status(HttpStatus.PAYMENT_REQUIRED).body("you have at least 10 points " + "(current: " + point + ")");
userAttributesService.updatePoint(point - 10);
...
}
I tried managing point to use JPA, it would handle user attribute using DB.
But, when I updated user attribute data in DB.
I tried managing point to connect JPA with keycloak DB.
And I found DB table for user attribute, and there is point value !
But it doesn't update in keycloak when I updated point in DB.... :'(