Use unitName attribute for injected JPA elements

This rule detects certain JPA PeristenceContext or PersistenceUnit annotations where the field name is the same as a persistence unit name that is defined in the persistence.xml file. This rule might require access to the persistence.xml file, which must be located in the META-INF folder. The following conditions trigger the rule:

• Marker Annotations:
• The annotation is defined on the field level.
• The field name is the same as a persistence unit name that is defined in the persistence.xml file.
• Normal Annotations:
• The annotation does not contain the attribute, name
• The annotation contains unitName , but does not contain name
• The annotation does not contain "name", or "unitName", and is declared on Field and the field name is the same as a persistence unit name defined in the persistence.xml file

The automatic fix will add the attribute unitName and/or name to JPA PeristenceContext or PersistenceUnit annotations.

Examples:

• PersistenceContext
@PersistenceContext
EntityManager myPersistenceContext;
• If myPersistenceUnit is defined as a persistenceUnit in the META-INF/persistence.xml file, the automatic fix will change this code to:
@PersistenceContext(unitName = "myPersistenceUnit", name = "myPersistenceUnit" )
EntityManager myPersistenceContext;
• PersistenceUnit
@PersistenceUnit EntityManagerFactory myPersistenceUnit;
• If myPersistenceUnit is defined as a persistenceUnit in the META-INF/persistence.xml file, the automated fix will change this code to:
@PersistenceUnit(unitName = "myPersistenceUnit", name = "myPersistenceUnit" )
EntityManagerFactory myPersistenceUnit;
• PersistenceUnit
@PersistenceUnit(unitName="someName")
EntityManager myPersistenceUnit;
• The automated fix will change this code to:
@PersistenceUnit(unitName = "someName", name = "someName" )
EntityManager myPersistenceUnit;