entitymanager

In my project , I use JSF+JPA+CDI+WildFly 8.2 in the persistence layer. I have a BasicDao , like this: public class BasicDao<M, K> { private org.jboss.logging.Logger logger = org.jboss.logging.Logger .getLogger("BasicDao"); @Inject @Primary protected EntityManager em; Class<M> mclass; public EntityManager getEm() { return em; } public void setEm(EntityManager em) { this.em = em; } @Transactional(value=TxType.NOT_SUPPORTED) public M find(K id){ return em.find(mclass, id); } @Transactional(value=TxType.REQUIRED) public void insert(M inst){ this.em.persist(inst); } @SuppressWarnings("unchecked")

I have an EntityManagerFactory for which I can create one (or multiple) EntityManager instances. I'm using a Servlet environment, and I've got one EntityManagerFactory wired up to the servlet (via the servlet context) which is shared for the lifetime of the servlet (and therefore, for all users). I can do one of the following: Create a single EntityManager for the lifetime of my servlet (e.g. shared between all users) Create one per user (so each user gets their own in the HttpSession) Create one per HTTP request (say, by instantiating a new one and closing it at the end of a doGet method)

I have 2 entities : Account and AccountRole . public class Account { private AccountRole accountRole; @ManyToOne(cascade = CascadeType.PERSIST, fetch = FetchType.EAGER) public AccountRole getAccountRole() { return accountRole; } . public class AccountRole { private Collection<Account> accounts = new ArrayList<Account>(); @OneToMany(mappedBy = "accountRole", fetch = FetchType.EAGER) public Collection<Account> getAccounts() { return accounts; } Problem comes when I take the accountRole from database and try to persist my Account . At this point I just created my account and role already exists

I have a LocalContainerEntityManagerFactoryBean as EntityManager instance. To quickly drop a full tables' content, I want to run the following code: @Service public class DatabaseService { @Autowired private EntityManager em; @Transactional public void clear() { em.createNativeQuery("TRUNCATE TABLE MyTable").executeUpdate(); } } Result: ERROR org.springframework.integration.handler.LoggingHandler: javax.persistence.TransactionRequiredException: Executing an update/delete query at org.hibernate.jpa.spi.AbstractQueryImpl.executeUpdate(AbstractQueryImpl.java:71) at org.springframework.cglib.proxy

Can anybody explain what is the difference between the Spring Framework's LocalContainerEntityManagerFactoryBean and LocalEntityManagerFactoryBean ? Basically JPA specification defines two types of entity managers . They are : i) Application-Managed : Application Managed entity manager means "Entity Managers are created and managed by merely the application ( i.e. our code )" . ii) Container Managed : Container Managed entity manager means "Entity Managers are created and managed by merely the J2EE container ( i.e. our code doesn't directly manages instead entity managers are created and