About EntityManagerFactory

forum_thread

system exception occurred during an invocation on EJB GuestDao

Hi, I am new to ObjectDB I was trying your eclipse/jee6/glassfish tutorial. Eclipse Luna, Glassfish 4. I am getting the following exception (see below) just after deploying the project. Can someone help me ?  Thanks ... by: java.lang.IllegalStateException: Unable to retrieve EntityManagerFactory for unitName null at ... by: java.lang.IllegalStateException: Unable to retrieve EntityManagerFactory for unitName null at ... by: java.lang.IllegalStateException: Unable to retrieve EntityManagerFactory for unitName null You may have missed one of the ...

 
api-jpa

javax.persistence.EntityManager

Interface used to interact with the persistence context.(Interface of JPA)

 
release

2.5.0

... Fixed a username/password issue in using EntityManagerFactory 's getMetamodel . Fixed a bug in ... EntityManager . Fixed a bug in concurrent EntityManagerFactory instantiation . Fixed a bug in ...

 
release

2.6.3

... JPA 2.1 methods. Implemented new JPA 2.1 EntityManagerFactory methods:  createEntityManager , unwrap . ... Fixed a username/password issue in using EntityManagerFactory 's getMetamodel . Fixed a bug in ...

 
release

2.2.6

... EntityManager . Fixed a bug in concurrent EntityManagerFactory instantiation . Fixed a bug in ...

 
release

2.2.5

... EntityManager . Fixed a bug in concurrent EntityManagerFactory instantiation . Fixed a bug in ...

 
api-jpa

javax.persistence.spi.PersistenceUnitInfo

Interface implemented by the container and used by the persistence provider when creating an javax.persistence.EntityManagerFactory.(Interface of JPA)

 
api-jpa

javax.persistence.PersistenceUnit

Expresses a dependency on an EntityManagerFactory and its associated persistence unit.(Annotation of JPA)

 
release

2.6.2

... JPA 2.1 methods. Implemented new JPA 2.1 EntityManagerFactory methods:  createEntityManager , unwrap . ... Fixed a username/password issue in using EntityManagerFactory 's getMetamodel . Fixed a bug in ...

 
forum_thread

use of Singleton into tomcat

hi all. i would write a class singleton that encapsulate the entitymanagerFACTORY    into it.(the entitymanagerFactory  IS A property of the only instance of class singleton. (the class singleton is not a Ejb!!!!!!!!!). into tomcat it not possible  use ejbs............. i have to manage the concurrency for the operations on db............... with a method static i can get the only instance of singleton for manage all operation on database. I get a instance of it into multiple servlet. ... i would write a class singleton that encapsulate the entitymanagerFACTORY    into it.(the entitymanagerFactory  IS A property of the only instance of class ...