I've resolved it.
The problem is that I created an Ebean transaction using following code that caused the trouble.
Ebean.beginTransaction();
try{
group.role = "A";
Ebean.update(group);
Ebean.commitTransaction();
} finally {
Ebean.endTransaction();
}
I never suspected that this could would have caused the problem as I put this code in another class file that is not related to this page. Then I changed to following code and everything worked as expected.
@Transactional
public void saveGroup(Group group){
group.role = "A";
Ebean.save(group);
.
.
}
Following documentation in play framework site helped me to identify the culprit. :)
Enhancement of direct Ebean field access (enabling lazy loading) is only applied to Java classes, not to Scala. Thus, direct field access from Scala source files (including standard Play 2 templates) does not invoke lazy loading, often resulting in empty (unpopulated) entity fields. To ensure the fields get populated, either (a) manually create getter/setters and call them instead, or (b) ensure the entity is fully populated before accessing the fields.