<
specification, business, programming> (EJB) A
server-side
component architecture for writing reusable
business logic
and
portable enterprise applications. EJB is the basis of
Sun's
Java 2 Platform, Enterprise Edition (J2EE).
Enterprise JavaBean components are written entirely in
Java
and run on any EJB compliant server. They are {operating
system},
platform, and
middleware independent, preventing
vendor
lock-in.
EJB servers provide system-level services (the "plumbing")
such as
transactions, security,
threading, and
persistence.
The EJB architecture is inherently transactional,
distributed,
multi-tier,
scalable, secure, and {wire
protocol} neutral - any
protocol can be used:
IIOP,
JRMP,
HTTP,
DCOM etc. EJB 1.1 requires
RMI for
communication with components. EJB 2.0 is expected to require
support for RMI/IIOP.
EJB applications can serve assorted clients:
browsers, Java,
ActiveX,
CORBA etc. EJB can be used to wrap {legacy
systems}.
EJB 1.1 was released in December 1999. EJB 2.0 is in
development.
Sun claims broad industry adoption. 30 vendors are shipping
server products implementing EJB. Supporting vendors include
IBM,
Fujitsu,
Sybase,
Borland,
Oracle, and
Symantec.
An alternative is Microsoft's MTS ({Microsoft Transaction
Server}).
http://java.sun.com/products/ejb/.
FAQ (http://java.sun.com/products/ejb/faq.html).
(2000-04-20)