1.7 Summary
EJBs are Java software components that run in a framework that supports distribution, load sharing, fault tolerance, security, and transaction management. The developer works within this framework to make the use of these features relatively straightforward. EJBs can use Java APIs like JDBC and JNDI to interact with external resources and can interoperate with other distributed object architectures, such as CORBA. The EJB framework is designed to support the notion of building an application with components from different vendors. The specification distinguishes between the 'component provider' and the 'application assembler,' even though these may, in practice, be the same person or group of people.
Effective use of EJBs requires that EJB server products be widely available. At the time of writing, there are a large number of vendors with products that support EJB 1.1, and a smallbut growingnumber that support EJB 2.0.
Table 1.1. Some products that support EJB technology.
Vendor |
Product |
Contact |
URL Evaluation support |
Notes |
Allaire Corp. |
JRUN |
Free developer version |
All java |
|
IONA |
iPortal |
Free 30-day |
|
|
Evidian |
JonAS |
Open Source |
|
|
Gemstone Systems, Inc. |
Gemstone/J |
Free 30-day |
|
|
Borland, Inc. |
Inprise |
Free trial version |
Supports the connector API |
|
Persistence Software, Inc. |
Power Tier |
Free 30-day |
|
|
Pramati Software, Inc. |
Pramati AS |
Free 30-day |
|
|
Sybase, Inc. |
EA Server |
Free 60-day |
|
|
BEA, Inc. |
WebLogic |
Free 30-day |
World's bestseller; EJB2.0 support |
|
Sub/AOL |
Sun ONE Application Server |
http://wwws.sun.com/software/products/ |
Trial versions on request |
|
(open source) |
jBoss |
Open source |
Very popular open source EJB server |
|
Oracle Corp. |
Oracle 8i/9I |
Trial versions for some platforms |
Very wide platform support |
|
IBM Corp. |
WebSphere |
Free 60-day |
Very wide platform support |