Hi java friends, i need some help in this diagram.
Here my questions:
1) In the book example, all Integration Tier components are DAOs, but they access only external resources (LDAP, Email Server...). So, if i want to create a DAO (despite the fact that EntityManager covers most part of basic operations) to access the application Database. This DAO class should be represented in Integration Tier too or in Persistence Tier?
2) There need to representate the EntityManager in the Persistence Tier?
3) In the example, no Application Database is represented, so, i need to put some information about this in my assumptions, or this is automatically understood?
1) Persistence layer because it only deals with persistence
2) I take it as implied because it is provided by Java itself.
3) List it as an assumption. As a general rule of thumb, put something as and assumption if you have even a shred of doubt as to whether it should be assumption. Seriously, I had A LOT of them. Better to have too many than not enough.