Session Beans (Enterprise JavaBeans)

B.2. Session Beans

B.2.1. Stateless Session Beans

Figure B-6. Life cycle state diagram of the stateless session bean

Figure B-7. Creation and removal of the stateless session bean

Table B-3 and Table B-4 summarize the operations that are legal for a stateless session bean.

Table B-3. Allowed Operations for Stateless Session Beans in EJB 1.1

Allowed Operations

Method

Container-Managed Transactions

Bean-Managed Transactions

setSessionContext()

EntityContext methods:

getEJBHome()

JNDI ENC contexts:

Properties java:comp/env

EntityContext methods:

getEJBHome()

JNDI ENC contexts:

Properties java:comp/env

ejbCreate()

ejbRemove()

EntityContext methods:

getEJBHome()

getEJBObject()

JNDI ENC contexts:

Properties java:comp/env

EntityContext methods:

getEJBHome()

getEJBObject()

getUserTransaction()

JNDI ENC contexts:

Properties java:comp/env

business methods

EntityContext methods:

getEJHome()

getCallerPrincipal()

isCallerInRole()

getRollbackOnly()

setRollbackOnly()

getEJObject()

JNDI ENC contexts:

Properties java:comp/env

Resource Managers java:comp/env/jdbc

EJB references java:comp/env/ejb

EntityContext methods:

getEJHome()

getCallerPrincipal()

isCallerInRole()

getEJObject()

getUserTransaction()

JNDI ENC contexts:

Properties java:comp/env

Resource Managers java:comp/env/jdbc

EJB references java:comp/env/ejb

ejbActivate()

ejbPassivate()

Not Supported

(stateless beans do not use these methods)

Not Supported

(stateless beans do not use these methods)

Table B-4. Allowed Operations for Stateless Session Beans in EJB 1.0

Allowed Operations

Method

Container-Managed Transactions

Bean-Managed Transactions

setSessionContext()

EntityContext methods:

getEnvironment()

getEJBHome()

EntityContext methods:

getEnvironment()

getEJBHome()

ejbCreate()

ejbRemove()

EntityContext methods:

getEnvironment()

getEJBHome()

getEJBObject()

EntityContext methods:

getEnvironment()

getEJBHome()

getEJBObject()

getUserTransaction()

business methods

EntityContext methods:

getEnvironment()

getEJHome()

getCallerPrincipal()

isCallerInRole()

getRollbackOnly()

setRollbackOnly()

getEJObject()

EntityContext methods:

getEnvironment()

getEJHome()

getCallerPrincipal()

isCallerInRole()

getEJObject()

getUserTransaction()

ejbActivate()

ejbPassivate()

Not Supported

(stateless beans do not use these methods)

Not Supported

(stateless beans do not use these methods)

B.2.2. Stateful Session Beans

Figure B-8. EJB 1.1 stateful session bean life cycle

Figure B-9. EJB 1.0 life cycle state diagram of the stateful session bean life cycle

Figure B-10. EJB 1.1 life cycle of a stateful session bean with session synchronization interface

Figure B-11. EJB 1.0 life cycle of the stateful session bean with session synchronization interface

Figure B-12. Creation and removal of stateful session beans

Figure B-13. Activation process in stateful session beans

Figure B-14. Transaction notification in SessionSynchronization session beans

Table B-5 and Table B-6 summarize the operations that are legal for a stateful session bean in EJB 1.1 and 1.0.

Table B-5. Allowed Operations for Stateful Session Beans in EJB 1.1

Allowed Operations

Method

Container-Managed Transactions

Bean-Managed Transactions

setSessionContext()

EntityContext methods:

getEJBHome()

JNDI ENC contexts:

Properties java:comp/env

EntityContext methods:

getEJBHome()

JNDI ENC contexts:

Properties java:comp/env

ejbCreate()

ejbRemove()

ejbActivate()

ejbPassivate()

EntityContext methods:

getEJBHome()

getCallerPrincipal()

isCallerInRole()

getEJBObject()

JNDI ENC contexts:

Properties java:comp/env

Resource Managers java:comp/env/jdbc

EJB references java:comp/env/ejb

EntityContext methods:

getEJBHome()

getCallerPrincipal()

isCallerInRole()

getEJBObject()

getUserTransaction()

JNDI ENC contexts:

Properties java:comp/env

Resource Managers java:comp/env/jdbc

EJB references java:comp/env/ejb

business methods

EntityContext methods:

getEJHome()

getCallerPrincipal()

isCallerInRole()

getRollbackOnly()

setRollbackOnly()

getEJObject()

JNDI ENC contexts:

Properties java:comp/env

Resource Managers java:comp/env/jdbc

EJB references java:comp/env/ejb

EntityContext methods:

getEJHome()

getCallerPrincipal()

isCallerInRole()

getEJObject()

getUserTransaction()

JNDI ENC contexts:

Properties java:comp/env

Resource Managers java:comp/env/jdbc

EJB references java:comp/env/ejb

afterBegin()

beforeCompetion()

EntityContext methods:

getEJHome()

getCallerPrincipal()

isCallerInRole()

getRollbackOnly()

setRollbackOnly()

getEJObject()

JNDI ENC contexts:

Properties java:comp/env

Resource Managers java:comp/env/jdbc

EJB references java:comp/env/ejb

Not Supported

(bean-managed transaction beans can not implement the SessionSynchronization interface)

afterCompletion()

EntityContext methods:

getEJBHome()

getCallerPrincipal()

isCallerInRole()

getEJBObject()

JNDI ENC contexts:

Properties java:comp/env

Not Supported

(bean-managed transaction beans can not implement the SessionSynchronization interface)

Table B-6. Allowed Operations for Stateful Session Beans in EJB 1.0

Allowed Operations

Method

Container-Managed Transactions

Bean-Managed Transactions

setSessionContext()

EntityContext methods:

getEnvironment()

getEJBHome()

EntityContext methods:

getEnvironment()

getEJBHome()

ejbCreate()

ejbRemove()

ejbActivate()

ejbPassivate()

EntityContext methods:

getEnvironment()

getEJBHome()

getCallerPrincipal()

isCallerInRole()

getEJBObject()

EntityContext methods:

getEnvironment()

getEJBHome()

getCallerPrincipal()

isCallerInRole()

getEJBObject()

getUserTransaction()

business methods

EntityContext methods:

getEnvironment()

getEJHome()

getCallerPrincipal()

isCallerInRole()

getRollbackOnly()

setRollbackOnly()

getEJObject()

EntityContext methods:

getEnvironment()

getEJHome()

getCallerPrincipal()

isCallerInRole()

getEJObject()

getUserTransaction()

afterBegin()

beforeCompetion()

EntityContext methods:

getEnvironment()

getEJHome()

getCallerPrincipal()

isCallerInRole()

getRollbackOnly()

setRollbackOnly()

getEJObject()

Not Supported

(bean-managed transaction beans can not implement the SessionSynchronization interface)

afterCompletion()

EntityContext methods:

getEnvironment()

getEJBHome()

getCallerPrincipal()

isCallerInRole()

getEJBObject()

Not Supported

(bean-managed transaction beans can not implement the SessionSynchronization interface)

B.2.3. EJB 1.1: Interactions Between Exceptions and Transactions

Table B-7 summarizes what happens to a transaction if an exception is thrown while the transaction is in process.

Table B-7. Exceptions and Transactions

Transaction Scope	Transactional Type Attributes	Exception Thrown	Container's Action	Client's View
Client Initiated Transaction Transaction is started by the client (application or bean) and is propagated to the bean method.	transaction-type = Container transaction-attribute = Required \| Mandatory \| Supports \|	Application Exception	If the bean invoked `EJBContext.setRollbackOnly()`, then mark the client's transaction for rollback. Rethrow Application Exception.	Receives the Application Exception. The client's transaction may or may not have been marked for rolled back.
		System Exception	Mark the client's transaction for roll back. Log the error. Discard the instance. Rethrow `TransactionRollbackException`.	Receives the `TransactionRollbackException` The client's transaction has been rolled back.
Container Initiated Transaction The transaction started when the bean's method was invoked and will end when method completes.	transaction-type = Container transaction-attribute = Required \| Requires New	Application Exception	If bean called `EJBContext.setRollbackOnly()`, then rollback the transaction and rethrow the Application Exception. If bean didn't explicitly rollback the transaction, then attempt to commit the transaction and rethrow the Application Exception.	Receives the Application Exception. The bean's transaction may or may not have been rolled back. The client's transaction is not affected.
		System Exception	Roll back the transaction. Log the error. Discard the instance. Rethrow `RemoteException`.	Receives the `RemoteException`. The bean's transaction was rolled back. The client's transaction is not affected.
Bean is not part of a transaction The bean was invoked but does not propagate the client's transaction and does not start its own transaction.	transaction-type = Container transaction-attribute = Never \| Not Supported \| Supports \|	Application Exception	Rethrow Application Exception	Receives the Application Exception. The client's transaction is not affected.
		System Exception	Log the error. Discard the instance. Rethrow `RemoteException`.	Receives the `RemoteException`. The client's transaction is not affected.
Bean Managed Transaction. The stateful or stateless session bean use the EJBContext to explicitly manage its own transaction.	transaction-type = bean transaction-attribute = Bean-Managed Transaction beans do not use transaction attributes.	Application Exception	Rethrow the Application Exception.	Receive the Application Exception. The client's transaction is not affected.
		System Exception	Roll back the transaction. Log the error. Discard the instance. Rethrow `RemoteException`.	Receives the `RemoteException`. The client's transaction is not affected.