Buisness logic docs updated

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

@@ -18,7 +18,6 @@ import org.springframework.stereotype.Service;
  * Service of GroupService which can find(optional), get(By Course, Groups
  * Ammount, Group By Id, find Not Existing Group), save, delete group.
  */
-
 @Service
 public class GroupService {
     @Autowired
@@ -27,34 +26,84 @@ public class GroupService {
     public GroupService() {
     }
 
+    /**
+     * find group with given properties
+     * 
+     * @param time     scheduled time for group as int of minutes passed from 00:00
+     * @param capacity capacity of group
+     * @param room     class room
+     * @return optional with Groups instance if found
+     */
     public Optional<Groups> find(int time, int capacity, String room) {
         return this.repo.find(time, room, capacity);
     }
 
+    /**
+     * find group with given properties
+     * 
+     * @param zajCykId proteprty from usos
+     * @param nrGr     group number
+     * @return optional with Groups instance if found
+     */
     public Optional<Groups> find(Integer zajCykId, Integer nrGr) {
         return this.repo.find(zajCykId, nrGr);
     }
 
+    /**
+     * find group with given properties
+     * 
+     * @param id course id of groups belogns to
+     * @return list of found groups
+     */
     public List<Groups> getGroupsByCourse(Long id) {
         return this.repo.getByCourse(id);
     }
 
+    /**
+     * save group to database
+     * 
+     * @param group insatnce to be saved
+     * @return new instance that has id form database
+     */
     public Groups save(Groups group) {
         return this.repo.save(group);
     }
 
+    /**
+     * delete from database
+     * 
+     * @param groups isntance to delete
+     */
     public void delete(Groups groups) {
         this.repo.delete(groups);
     }
 
+    /**
+     * get hom manyh groups are in database in general
+     * 
+     * @return int - groups ammount
+     */
     public int getGroupsAmmount() {
         return (int) this.repo.count();
     }
 
+    /**
+     * find group with given properties
+     * 
+     * @param id group id
+     * @return optional with group if found
+     */
     public Optional<Groups> getGroupById(Long id) {
         return this.repo.findById(id);
     }
 
+    /**
+     * get wich of provided id is not existind groups
+     * 
+     * @param ids list of ids to check
+     * @return optional with id that is not group if found. If there is multiple
+     *         will be returned first found
+     */
     public Optional<Long> findNotExistingGroup(List<Long> ids) {
         for (Long oneId : ids) {
             if (this.repo.existsById(oneId) == false) {