OSGi without the Eclipse
It's become common to equate OSGi with Eclipse or Equinox, but in fact other OSGi implementations exist. This post from JW blogger Oleg Mikheev fills a much needed gap - walking through the process of developing a Hello World bundle with Apache Felix and the IDE of your choice.

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Sun's BluePrints for J2EE

Learn the basics of designing J2EE applications -- from one handy guide

By Ethan Henry, JavaWorld.com, 02/21/00

Sun's recent release of the Java 2 Enterprise Edition reference implementation, or J2EE RI (see Resources for downloading information), provides an implementation of all the J2EE functionality, including technologies such as Enterprise JavaBeans (EJB), CORBA, XML, servlets, and JavaServer Pages (JSP). Along with the libraries and examples in the reference implementation package comes a new whitepaper from Sun describing its vision of how Java applications should be designed and built.

(As a side note, Sun has outsourced part of the reference implementation for the Servlet and JSP APIs by releasing it under an open source license to the Apache project. The Tomcat server, from the Apache Jakarta group [see Resources] provides the reference implementation in a freely usable form. Combined with the Apache Web server, the Tomcat server should help accelerate the adoption of J2EE by providing a high-quality, cross-platform implementation of these two APIs.)

Normally a whitepaper from a big company isn't headline news, but at 266 pages, the "J2EE Application Programming Model" (APM) isn't your typical whitepaper. The APM is a summary (if a long one) of Sun's view of how to build an enterprise Java application and where Java fits into the software development landscape. For developers who already know how to build distributed applications using Java or other technologies like CORBA or DCOM, only the details of the APM present anything new. For developers who haven't looked extensively at J2EE or for developers unfamiliar with distributed systems, the APM provides a good, if verbose, introduction.

As part of the official J2EE launch in December, the APM has been renamed the "Sun BluePrints Design Guidelines for J2EE." The new name reflects its inclusion in Sun's BluePrints best-practices series of articles and whitepapers. But because "Sun BluePrints Design Guidelines for J2EE" is too long to write over and over, I'll continue to refer to the document as the APM. The final version of the J2EE BluePrint document will be published by Addison-Wesley sometime this year.

Before going into the details of the APM, I should warn you that if you download the APM and start reading it, you're probably going to skip over quite a bit. The APM goes from very high-level views of distributed systems, talking about things such as the multitier distribution model, to very low-level details such as the types of transaction handling supported by EJBs. Much of this highly detailed information is lifted from other sources such as the EJB documentation and other previously published J2EE specifications, but you can rest assured that if you actually print all 266 pages, you'll probably get good use of the document over time, as you won't also have to print out the whitepapers for EJB, JSP, and so on.

What's in the APM?

The APM sets the stage for Sun's guidelines by describing the needs of "enterprise computing" -- that is, the needs of those who create systems that manage information inside businesses. These systems enable activities such as information sharing, information warehousing and management, and, most important in today's Internet economy, ecommerce.

Resources