jqassistant CDI Plugin

jQA-CDI.asciidoc

Concepts

Bean

Managed Bean

• Concrete POJO

  • No-arg constructor

  • Constructor with @Inject

• Objects returned by Producers

• EE Spec

  • Session Bean

  • DataSource, PersistentContext

Injection Points

• Field Injection

MATCH
     (a:Type)-[:DECLARES]->(member:Field:Cdi:InjectionPoint)
RETURN
     DISTINCT a.fqn AS FieldInjectionTarget

• Constructor Injection

MATCH
     (a:Type)-[:DECLARES]->(member:Method:Cdi:InjectionPoint)
WHERE member.name = "<init>"
RETURN
     a.fqn AS ConstructorInjectionTarget

• Parameter Injection

  • Setter Methods

MATCH
     (a:Type)-[:DECLARES]->(member:Method:Cdi:InjectionPoint)
RETURN
     a.fqn AS InjectionTarget, member.name AS SetterInjectionPoint

• Initializer Method

• Observer, Producer, Disposer Methods

Injection Targets

POJOs, Session Beans, Servlets

Bean Scopes

ApplicationScoped, RequestScoped, SessionScoped, ConversationScoped, Dependent

Alternative Bean

Specialized Bean

Stereotype

Qualifiers

Producer Methods

A producer method may be declared by annotating a method with the @javax.enterprise.inject.Produces annotation.

Specialized Producer Methods

Producer Fields

Disposer Methods

Disposer Fields

Decorators

Interceptors

Container Lifecycle Events

CDI Event Producer

MATCH
     (a:Type)-[:DECLARES]->(member:Field:Cdi:InjectionPoint)-[:OF_TYPE]->(injectType:Type)
WHERE
     injectType.fqn = "javax.enterprise.event.Event"
RETURN
     a.fqn AS CdiEventProducer

CDI Event Consumer

MATCH
     (a:Type)-[:DECLARES]->(member:Method)-[:HAS]->(p:Parameter)-[:ANNOTATED_BY]->()-[:OF_TYPE]->(injectType:Type)
WHERE injectType.fqn = "javax.enterprise.event.Observes"
RETURN
      a.fqn AS CdiEventConsumer

CDI Singleton

Singleton scoped classes

MATCH
	(t:Type)-[:ANNOTATED_BY]->()-[:OF_TYPE]->(scopeType:Type)
WHERE
	scopeType.fqn="javax.inject.Singleton"
RETURN
	t.fqn AS cdiSingleton

Methods producing singletons

MATCH
	(t:Type)-[:DECLARES]->(m:Method),
	(m)-[:ANNOTATED_BY]->()-[:OF_TYPE]->(scopeType:Type)
WHERE
	scopeType.fqn="javax.inject.Singleton"
RETURN
	m.signature, t.fqn AS cdiSingletonProducer

Constraints

Avoid Bean Names in injection points

@Inject @Named ( "ordersBean" )
private OrdersBean orderBean ;

MATCH
  (t:Type)-[:DECLARES]->(member:Cdi:InjectionPoint),
  (member)-[:ANNOTATED_BY]->()-[:OF_TYPE]->(a:Type)
WHERE
  a.fqn = "javax.inject.Named"
RETURN
  distinct t.fqn AS invalidBean

Avoid setter injection

@WebServlet(urlPatterns = "/itemServlet")
public class ItemServlet extends HttpServlet {

    private NumberGenerator numberGenerator;
    private ItemEJB itemEJB;

    @Inject
    public void setNumberGenerator(@ThirteenDigits NumberGenerator numberGenerator) {
        this.numberGenerator = numberGenerator;
    }

    @Inject
    public void setItemEJB(ItemEJB itemEJB) {
        this.itemEJB = itemEJB;
    }
    ...
}

Avoid Qualifier Hell

Use Enums on qualifiers if multiple managed bean implementations are available.