What do the different kinds of arrows between classes and interfaces in this Hibernate diagram mean?

Question

I am trying to understand the following diagram from http://docs.jboss.org/hibernate/orm/5.2/userguide/html_single/Hibernate_User_Guide.html for relationships between Hibernate's classes.

I am not quire sure what the different kinds of arrows mean, and I guess they are not following UML diagram specifications. Could someone explain what the different kinds of arrow mean? Thanks.

Answer 1

The circled Is and C (likely for interface and class) are no UML standard. However, you can adorn stereotyped classes with icons at your wish. Though I doubt that the standard classes here need a stereotype to mark them as "standard class".

I'd guess that the

• dotted arrows with filled triangles should be Realizations (since they point to interfaces). These would need an unfilled triangle in UML to be correct.
• The same goes for the solid lines with filled triangle which are likely generalizations. UML needs unfilled triangles here.

Anything else (which isn't much) seems fine.

• Dependency with dashed line and open triangle
• Directed associations with composite shown by filled diamond.

Answer 2

If i understand it, it is not an UML diagram.

• The arrow between SessionFactory and SessionFactoryImpl coudld be a generalization, but in UML the arrow is empty not filled as in your diagram

• The arrow between Transaction and TransactionImpl seems to be a realization relation, but in UML there is no composition but a dash line with an empty arrow

• The arrow between TransactionImpl and EntityTransaction may be a dependency but in UML this is an open arrow.