Primitive type in JPA mapping. What if the database column may be NULL?

Question

Given this class mapped with JPA (using JPA 1.0 and Hibernate):

@Entity
public class Foo {

    private int bar;

    /* ... */
}

1. What happens if I try to load a record which has the BAR column set to NULL?
2. Can I specify how to set the bar field when the corresponding column is NULL?

Notes

I know this is not a best practice. The question is more out of curiosity and it is inspired by this situation:

• The database table is a staging table: adding a NOT NULL constraint is impractical. Bad data is expected, and the point of my code is to validate, clean up and/or reject data before loading it into the "real" database.
• I have acceptable default values for some fields. For example, a boolean flag which should default to false.

Answer 1

I would rather use objects if a column may contain null value because Matheus's idea introduces false data. NULL <> 0!