Explanation/Reference:
The exception will be thrown within the FooBean container.
A standard EJBException will be thrown.
The EJBException is thrown to report that the invoked business method or callback method could not be completed because of an unexpected error (e.g. the instance failed to open a database connection).
Note:
Transaction Attributes
A transaction attribute controls the scope of a transaction. Figure below illustrates why controlling the scope is important. In the diagram, method-A begins a transaction and then invokes method-B of Bean-2.
When method-B executes, does it run within the scope of the transaction started by method-A, or does it execute with a new transaction? The answer depends on the transaction attribute of method-B.
* RequiresNew Attribute
If the client is running within a transaction and invokes the enterprise bean's method, the container takes the following steps:
1. Suspends the client's transaction
2. Starts a new transaction
3. Delegates the call to the method
4. Resumes the client's transaction after the method completes
If the client is not associated with a transaction, the container starts a new transaction before running the method.
You should use the RequiresNewattribute when you want to ensure that the method always runs within a new transaction.
Reference: The Java EE 6 Tutorial, Container-Managed Transactions