Null « EntityManager « JPA Q&A

1. JPA entityManager is null in Pointcut

I have defined a pointcut using the @Aspect annotation in my class. I configure the pointcut using a custom annotation which I have defined in my context:

<aop:aspectj-autoproxy proxy-target-class="true"/>
<!-- Messaging pointcut -->
<bean id="messagePointcut" ...

2. EntityManager became NULL after a while (about 10m)

in my JavaEE 6 application (JBoss 6.0.0.Final) I have a class hierarchy outlined like this

@Stateful public class UserFacade
  @Inject @MyRepository
  private EntityManager em;

@Stateful public class UserBl
  @EJB private ...

3. JPA EntityManager is not initialized (null)

Im new to JPA I generated the following code using reverseEngineering tool (Hibernate). But the entitymanager always null. I do not know what to do please guide me. Is there anything that I ...

4. How to avoid overwriting of non-null values with null values?

I'm using spring MVC for receiving a JSON from client and automatically create an object from it. The problem is that the client doesn't send to server all the fields that ...

6. EntityManager find() and null return

Hi, Would someone explain to me under what circumstances a find returns a null when, in fact, a row exists with that primary key. According to Dan (or rather his fine book) find() always hits the database. The underlying DB is MySQL 5.1.48 with the 5.1.10 Connector/J. It might be relegated to when the application is under heavy load. The particular ...

7. Hibernate 3.5 @OneToOne EntityManager find() returns null

I think I found a bug in Hibernate 3.5, because the code above works in 3.2.2 branch. Whenever I have a @OneToOne relation in this fashion, entityManager is not able to find the entity. The find() method allways return null!!!!!! Code: @Entity @Table(name = "cheque") @TableGenerator(name = "chequeTG", table = "sequenciador", pkColumnName = "tabela", valueColumnName = "valor", allocationSize = 1) public ...