The layers defined within each project (considering also al part of
persistence that we said is optional) are:
- Persistence
- Service Layer
- System Api
- Service Api
- Rest
- Websocket
The persistence layer consists of a class that generalizes
basic save and search operations. Thus by extending the framework
class there is no need to write any persistence logic.
The Service layer consists of 2 components that,
implementing two interfaces SystemApi and Api.
- SystemApi: classes that perform
validation logic on beans (leveraging javax.validation
annotations and automating error handling) before they are sent
to the persistence layer
- Api:
classes that invoke *SystemApi methods but before doing so
verify that the user has permissions to perform certain
operations
In essence, then, the main difference between the two types of
SystemApi and Api services relates to the fact that the
former does not perform any verification of permissions. This is
useful because when you need to do a system operation you can directly
inject the system instance thus bypassing the System permission. The
second one, on the other hand, before any operation checks the user’s permissions.
The Rest Layer is based on Apache CXF and provides basic
tools to define services that require authentication or not, swagger
documentation generation.
The Websocket Layer is optional but allows a websocket to be
defined easily without too much effort within Karaf.
