Head First EJB

Call stack of the checkOut() method

1. ut.begin() is called, and the transaction starts.

   

2. ut.begin() completes, and now the checkout() method is running in a transaction (tx A).

   

3. validateCredit() is called and runs in the same transaction as checkOut().

   

4. validateCredit() completes (pops off the stack) and the checkOut() method is still running in tx A.

   

5. checkInventory() is called and runs in the same transaction (tx A).

   

6. checkInventory() completes and pops off the stack. The transaction (tx A) is still open.

   

7. commit() is called, which ends the transaction.

   

8. commit() completes, and now checkOut() is running without a transaction.

   

9. doNonTxStuff() is called without a transaction.

Sharpen your pencil

Using this code listing, ...