使用多个EJB将数据保存在CDI托管bean的一个事务中

Question

I have following scenario:

I have a JSF Dialog(Primefaces) with some tabulators in there. The dialog has "OK" Button. If click "OK" all the data in tabulators should be saved in one transaction. The problem is each tabulator has associated (CDI) session scoped backing bean, and each backing bean has "save"-Method to save the data of particular tabulator with the help of stateless EJB.

How can I do so that all the EJB related code will be saved in one transaction.

What I already know:

1. Stateful EJB. (This method need to rewrite stateles EJB calls and delegate them to stateful EJB).
2. write global stateless EJB that saves the data(this method need the data from each session bean)

It is possible that the tabulator (CDI) session backing bean will be reused in another place. So it should be independent. What do you think is a good method ?

EDIT: Pseudocode:

@SessionScoped
class BackingBeanTab1 {
   //CDI session scoped bean for Info in Tab1
   String firstname;
   String lastname;

   @Inject StatelessTab1DAO dao1;

   public void save () {
      dao1.save(..);
   }
}

@Stateless
class StatelessTab1DAO {
   public void save (...);
}

Similar for Tab2 ...

@SessionScoped
class BackingBeanTab2 {
   //CDI session scoped bean for Info in Tab1
   int debit;

   @Inject StatelessTab2DAO dao1;
   public void save();
}

@Stateless
class StatelessTab2DAO {
   public void save (...);
}

With this design I can reuse each tabulator. But what good possiblites are ther to save in one transaction ?

Answer 1

It depends on your application, but in general data from the tabs should be kept in temporary storage (session or statefull bean) and then saved on dialog OK button. There could be at least a few options:

• use stateful bean as facade

Your facade implements all methods of your stateless beans and stores data in its variables, once the OK button is clicked it invokes save method on facade, facade calls each stateless session bean to save the data - all in one transaction either saved or rolled back.

• use http session for temporary storage

This is your current design as I believe from description. But your backing beans should only keep data in session, not save it to the database (as my understanding is that all tabs must be filled for data to be valid). Then when the OK button is clicked you could use:

either the UserTransaction object to begin the transaction, call all session beans with required data, and commit transaction

or create a statless facade and call this facade with all required data (which would call all other session beans like in a stateful example), and let the container to handle transaction management.

Answer 2

if you like to code in some other path than you can try this,

for the each cdi validation you can use ajax call so while filling the data in table the inserted data will be validate accordingly .And for saving the data in one transaction you may need cmt or bmt transaction in ejb bean and if your using bmt than the start transaction and commit transaction should be done by developer onle