FF-255 Added remaining logic.

Author: open-schnick

src/main/java/de/filefighter/rest/domain/user/business/UserBusinessService.java

@@ -114,6 +114,9 @@ public UserEntity registerNewUser(UserRegisterForm newUser) {
 
         for (long id : userGroups) {
             try {
+                if (id == Groups.SYSTEM.getGroupId())
+                    throw new UserNotRegisteredException("New users cannot be in group '" + Groups.SYSTEM.getDisplayName() + "'.");
+
                 groupRepository.getGroupById(id);
             } catch (IllegalArgumentException exception) {
                 throw new UserNotRegisteredException("One or more groups do not exist.");
@@ -162,7 +165,7 @@ public void updateUser(long userId, UserRegisterForm userToUpdate, User authenti
         if (null == userEntityToUpdate)
             throw new UserNotUpdatedException("User does not exist, use register endpoint.");
 
-        if(Arrays.stream(userEntityToUpdate.getGroupIds()).asDoubleStream().anyMatch(id -> id == Groups.SYSTEM.getGroupId()))
+        if (Arrays.stream(userEntityToUpdate.getGroupIds()).asDoubleStream().anyMatch(id -> id == Groups.SYSTEM.getGroupId()))
             throw new UserNotUpdatedException("Runtime users cannot be modified.");
 
         Update newUpdate = new Update();
@@ -188,8 +191,8 @@ private boolean updateGroups(Update newUpdate, long[] groupIds, boolean authenti
         if (null != groupIds && groupIds.length != 0) {
             try {
                 for (Groups group : groupRepository.getGroupsByIds(groupIds)) {
-                    if( group == Groups.SYSTEM)
-                        throw new UserNotUpdatedException("Users cannot be added to the '"+ Groups.SYSTEM.getDisplayName()+"' Group");
+                    if (group == Groups.SYSTEM)
+                        throw new UserNotUpdatedException("Users cannot be added to the '" + Groups.SYSTEM.getDisplayName() + "' Group");
                     if (group == Groups.ADMIN && !authenticatedUserIsAdmin)
                         throw new UserNotUpdatedException("Only admins can add users to group " + Groups.ADMIN.getDisplayName() + ".");
                 }