Thursday, December 11, 2008

LinkedIn Flex group hits membership limit

From Adobe Technical Evangelist Ben Forta comes word that the LinkedIn Flex Developers Group is now full to capacity and can accept no more members.

Apparently, LinkedIn groups can have a maximum of 3000 members, and that's how many the Flex-dev group now has. (I wonder who the genius was that hard-coded that limit?) Forta says he is sitting on 50-some-odd requests to join, and can't approve them. Moreover, he pinged LinkedIn Customer Services to ask if there was a way to raise that limit. He was told he can't approve any more requests. "If the limit gets raised," Forta says, "I'll let you know (and will approve those in the queue)."

Tuesday, December 09, 2008

SlingPostServlet demystified

One of the neatest things about Apache Sling (the JCR-based application framework) is its easy-to-use REST API, which allows you to do CRUD operations against a Java Content Repository using ordinary HTML web forms (or should I say, ordinary HTTP POST and GET), among many other interesting capabilities. The magic happens by way of a class called SlingPostServlet. Understanding that class is key, if you want to leverage the power of Sling without writing actual Java code.

Turns out there's an exceptionally thorough (and readable) discussion of the many capabilities of the SlingPostServlet at the Sling incubation area of You can think of it as the fully exploded version of Lars Trieloff's Cheat Sheet for Sling (an excellent resource). It's the next best thing to reading the source code.

Monday, December 08, 2008

MS Office apps as services

According to Information Week, Tibco and OpenSpan have "teamed up to make parts of Microsoft's Office applications available as services for inclusion in an enterprise service-oriented architecture."

OpenSpan has (in the words of a rather breathless reporter) "demonstrated that it's possible to generate mashups of Microsoft Office applications without changing the underlying application code."

On a superficial level, this is the kind of thing that people do routinely with OpenOffice running in server mode. (Various content management systems use OO to do document transformations on the server. The OO developer documentation shows how to set this up.)

I gather the OpenSpan stuff has tooling for making it easy to create Office-service mashups. It's a good idea and I wish such tooling existed for OpenOffice. It'll be interesting to see if Tibco and OpenSpan score any OEM deals with CMS vendors.

Friday, December 05, 2008

How OSGi changed one person's life

Peter Kriens has written a really nice article for ACM Queue called How OSGi Changed My Life. Go here to read it online. It's a high-level overview for people who are still trying to grok the whole OSGi phenomenon.

OSGi is a game-changing technology, IMHO, because it brings familiar SOA precepts to ordinary POJO programming. (How's that for acronym abuse?) POJOs end up having fewer unwanted intimacies, and if you run them inside Spring inside OSGi, the POJOs don't have to know so much about the runtime framework, either. Compositionality is greatly facilitated in OSGi; the level of abstraction is high; the benefits are numerous and far-reaching. I see OSGi as revitalizing Java programming for enterprise.

Good tooling for OSGi is still scarce. (Doing "Hello World!" is much harder than it should be.) I suspect that will change very soon, though. Meanwhile, OSGi is quite pervasive already (it's in quite a few products, though seldom advertised), and I look for 2009 to be the year when OSGi finally goes double-platinum.

Tuesday, December 02, 2008

Exception-throwing antipatterns

Tim McCune has written an interesting article called Exception-Handling Antipatterns, at (a fine place to find articles of this kind, BTW). The comments at the end of the article are every bit as stimulating as the article itself.

McCune lists a number of patterns that (I find) are very widely used (nearly universal, in fact) in Java programming, such as log-and-rethrow, catch-and-ignore, and catch-and-return-null; all considered evil by McCune. My comment is: If those are antipatterns, the mere fact that such idioms are so ubiquitous in real-world Java code says more about the language than it does about programmers.

I've always had a love-hate relationship with the exception mechanism. On the whole, I think it is overused and overrated, at least in the Java world, where people seem to get a little nutty about inventing (and sublcassing) custom exceptions and ways to handle them, when they should probably spend that energy writing better code to begin with.

Monday, December 01, 2008

Get paid for being job-interviewed

At last, an online service that deters head hunters from pestering me.

The unusual promise made by NotchUp is that potential employers who want to contact you directly (avoinding the expensive services of a professional placement agency) will actually pay you to agree to an interview. All you have to do is sign up with NotchUp, and wait for the phone to ring. (And wait. And wait.)

How much will you get paid? The NotchUp folks have put a fee calculator on their site. It shows that an IT professional with 10 years of experience can expect to receive $380 per interview.

NotchUp membership is free to interviewees, but you have to go through an application process and be accepted. Which already sounds fishy to me.