[java] Java Persistence API (JPA) Entity Rule: Non-final Instance Variables

[numeralnathan]

Proposed Rule Name: JPANonFinalInstanceVariables

Proposed Category: Bug

Description:

When a class is annotated with JPA's @Entity, there are certain requirements placed on the class. Please create a rule that requires the instance variables to be non-final.

Note: Hibernate allows for final instance variables but lazy-loading will not work.

Code Sample:

The following class will cause a problem at runtime because it has a final instance variable.

@Entity
class MyEntity
{
   private static final COUNT = 5;

   private final int m_data;
}

The following class is correct.

@Entity
class MyEntity
{
   private static final COUNT = 5;

   private int m_data;
}

Possible Properties:

Can you think of some properties?