Figure 1: Transaction processing application functions and iSeries and J2EE support
Application function	iSeries support	J2EE support
User interface for display and input	Display file DDS and HLL I/O	HTML, XML, servlets, JSPs
Database access to retrieve and update persistent data	Database DDS and HLL I/O, or SQL DDL and DML	JDBC, JDO, entity EJBs
Data validation and processing	HLL	Servlets, session EJBs, POJOs
Data validation and processing Transaction support, including concurrent transaction isolation and "all or none" updates	DB2 for iSeries commitment control, HLL and SQL executable commit/rollback statements	JTA (including callable commit and rollback methods), EJB declarative transactions
Security, including user identity, logon authentication, and access authorization	OS/400 user profile and group profile objects, OS/400 work management sign-on support, OS/400 object-level security, program-adopted authority	User registries, Web container log on support, Web component authorization, EJB method-level authorization, EJB roles and groups, programmatic security, principal mapping