Should jQAssistant's EJB3 plugin create the Concepts listed in the manual?

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I'm trying a couple of jQAssistant plugins, in this case the EJB3 plugin.

I think I haven't grasped the idea of Concepts. I was expecting Node labels like "Ejb", "Local" and "Remote" to appear after scanning a Maven module that contains some EJBs.

However, I don't see anything like that.

But if I run the query in the manual, for instance

MATCH (t:Type)-[:ANNOTATED_BY]->()-[:OF_TYPE]->(a:Type)
WHERE a.fqn="javax.ejb.Local"
SET t:Ejb:Local
RETURN t AS LocalBean

then I see the label "Local" - well, the query sets it, after all :-)

This is probably a newbie question... But am I supposed to run the queries after the scan? Or should those labels be set by the EJB3 plugin?

jqassistant
1 Answers

A scan only imports "raw" data into the graph database, in case of Java it just represents the structure of the bytecode with elements like packages classes, methods, fields, annotations or invocations.

The purpose of concepts is to enrich this information with higher level abstractions, e.g. a node representing a Java class annotated with @Local is labeled with Ejb and Local for easier usage by other concepts or constraints. Those then can just rely on the label Ejb to perform checks, e.g. for correct location in service layer packages. These themselves would have been labeled by a concept according to project specific naming rules:

[[adr:ServiceLayer]]
[source,cypher]
.The package named `service` within the root package represents the `Service` `Layer`.
----
MATCH
  (root:Package)-[:CONTAINS]->(serviceLayer:Package)
WHERE
  root.fqn = "my.project.root"
  and serviceLayer.fqn = "service"
SET
  serviceLayer:Service:Layer
RETURN
  serviceLayer as `Service Layer`

The constraint would now depend on both concepts and use a query like this:

[[adr:EjbsMustBeLocatedInServiceLayer]]
[source,cypher,role=constraint,requiresConcepts="ejb:*,adr:ServiceLayer"]
.All EJBs must be located in the service layer.
----
MATCH
  (ejb:Ejb)
WHERE NOT
  (:Service:Layer)-[:CONTAINS*]->(ejb)
RETURN
  ejb as `EJB Outside Service Layer`
----

Concepts must be applied explicitly, usually they are defined as dependency:

user_29122000
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