Add missing service

Co-authored-by: [Mahgs] <maxoerter@gmx.de>
Co-authored-by: Christoph <tobi@urpost.de>

src/main/java/mops/gruppen2/service/InviteLinkRepositoryService.java

@@ -0,0 +1,26 @@
+package mops.gruppen2.service;
+
+import mops.gruppen2.domain.dto.InviteLinkDTO;
+import mops.gruppen2.repository.InviteLinkRepository;
+import org.springframework.stereotype.Service;
+
+import java.util.UUID;
+
+@Service
+public class InviteLinkRepositoryService {
+
+    private final InviteLinkRepository inviteLinkRepository;
+
+    public InviteLinkRepositoryService(InviteLinkRepository inviteLinkRepository) {
+        this.inviteLinkRepository = inviteLinkRepository;
+    }
+
+    public long findGroupIdByInvite(String link) {
+        return inviteLinkRepository.findGroupIdByLink(link);
+    }
+
+    public void saveInvite(Long group_id, UUID link) {
+        inviteLinkRepository.save(new InviteLinkDTO(null, group_id, link.toString()));
+    }
+
+}