Added endpoints

buisnesslogic/src/main/java/com/plannaplan/services/GroupService.java

@@ -1,5 +1,7 @@
 package com.plannaplan.services;
 
+import java.util.List;
+
 import com.plannaplan.entities.Groups;
 import com.plannaplan.repositories.GroupRepository;
 
@@ -18,6 +20,10 @@ public class GroupService {
         return this.repo.find(time, room, capacity);
     }
 
+    public List<Groups> getGroupsByCourse(Long id) {
+        return this.repo.getByCourse(id);
+    }
+
     public void save(Groups group) {
         this.repo.save(group);
     }