Dave Johnson on open web technologies, social software and Java
Nick Lothian tweeted about this JavaOne presentation on LinkedIn because it mentions the ROME RSS/Atom feed parser. I'm really sorry I missed it at JavaOne. What's particularly interesting to me are the diagrams that explain how the LinkedIn architecture has evolved to scale up to 22 million users. Here's an example:
Struts 2 is my favorite Java web framework these days; it's REST-friendly, simple, easy to use, very flexible and the only thing it has with its creaky old Struts 1.x parent is the fact that it's an action framework rather than a component framework like JSF. As most of my readers probably already know, Struts 2 is based on WebWork/XWork the framework that powers JIRA and Confluence, two of the coolest Java webapps around.
Apparently, I'm not alone in this thinking -- I keep on running into folks at JavaOne who feel the same way. But unfortunately, Struts 2 docs are lacking, so I was very happy to see two new books on Struts 2 at the JavaOne bookstore. There's Struts 2 in Action, a rewrite of the classic Manning book, and Practical Apache Struts 2 Web 2.0 Projects from Apress.
I picked up a copy of Struts 2 in Action on Monday and it looks great so far, but I've only skimmed it. I'll let you know what I think once I dig-in on the flight home.
If you're at JavaOne, check out TS-5739 - Hands-on Struts2 by Ian Roughley (author of the Apress book) today at 10:50 AM in Esplanade 307/310.
I've been very happy with the choice of Struts 2 for Roller, but I still follow JSF because it's the Java standard. A couple of articles by Ryan Lubke about what's coming in JSF 2.0 got me thinking about JSF again.
One of my problems with JSF is REST. REST fans say JSF is inherently RESTless because every JSF request is a POST. JSF advocates say JSF can do GET and bookmarkable URLs if necessary and that's good enough.
Fortunately, the plans for JSF 2.0 indicate that REST improvements are coming:
Unfortunately, it sounds like all they're planning to do is make it easier to create bookmarkable URLs and add some support for the JSF-311 REST API. Why can't the goal be to make JSF applications RESTful by default? Why can't JSF ensure that POST is only used when required by the application (not the framework) and JSF URLs are simple, clean and always bookmarkable.
For Java developers starting out with RSS and Atom, here are some notes to help you figure out the differences between the Java.net ROME and Apache Abdera (incubating) projects.
ROME is a set of Java tools for parsing, fetching and generating all forms of RSS and Atom feeds. The core ROME library is relatively small and depends only on the somewhat creaky old JDOM XML parser. Available separately are modules to support various feed extensions such as OpenSearch, iTunes, GeoRSS, etc. ROME was originally developed and open sourced by Sun Portal dev team members in 2004.
ROME Propono is a subproject of ROME that supports publishing/editing entries and files to blog servers and AtomPub servers. Propono is made up of three parts: 1) a Blog Client library can publish via either the old lagacy MetaWeblog API or the shiny new AtomPub protocol, 2) an AtomPub client that publishes only via AtomPub and 3) a framework for creating AtomPub servers. Propono was developed by Ramesh Mandava and Dave Johnson, based on code from RSS and Atom in Action and open sourced as part of the Sun Web Developer Pack in 2007.
Abdera is a set of Java tools for working with Atom feeds and AtomPub protocol. This includes a parser, writers, an AtomPub client and a framework for creating AtomPub servers. Abdera's Atom feed parser uses STAX, so it uses less memory and is faster than ROME. Abdera's Atom feed support is more comprehensive than ROME's and it supports signatures, encryption, Atom to JSON, extensions for Threading, Paging, GeoRSS, OpenSearch, GoogleLogin, etc. etc. Abdera was developed by IBM and contribued to Apache in 2006.
Now let's compare frameworks. The pros and cons of ROME are:
The pros and cons of Abdera are:
There you have it. ROME and Abdera folks: think that's a fair comparison? Are you a ROME or Abdera user? How would you like to see these frameworks move forward?
Over the holidays I avoided doing anything directly related to my current set of work tasks. Sun went quiet, which helped, and I ignored the messages that piled-up in the Roller user and dev lists. It was so quiet that I had time for a fun little project: a JMaki plugin for Roller.
<html> <head><title>JMaki test page</title></head> <body> <h1>JMaki test: dojo.clock</h1> $jmaki.addWidget("dojo.clock") <h1>JMaki test: yahoo.dataTable</h1> $jmaki.addWidget("yahoo.dataTable", "/roller/xhp?id=rss","","") </body> </html>
And here's what that page looks like when displayed by Roller:
I'll write more about the plugin once I install it on this site. If you want some details about how the plugin was developed, you can read the email that I sent to the JMaki dev list: JMaki for Roller issues and suggestions. It links to the Java source code for the plugin.
I'm always happy to see Roller used in new sites, projects and products. Here's an interesting new example that I've been meaning to blog for a while now. Phillip Rhodes is working on building what he calls OpenQabal a "social software operating system." The project integrates a set of social software applications, including Roller and JavaBB, via Single Sign-On (SSO), a common look-and-feel and Semantically-Interlinked Online Communities (SIOC). He explains it all in an lengthy and informative blog post on the project's JRoller.com blog.
I'd never heard of SIOC before. Here's the executive summary:
Semantically-Interlinked Online Communities SIOC or is a framework aimed at connecting online community sites and internet-based discussions. Currently, online communities (boards, blogs, etc.) are like islands - they contain valuable information but are not well connected. SIOC allows us to interlink these sites, and enables the extraction of richer information from various discussion services.
Sounds like it could be pretty darn useful. But then again, I spent a little time exploring the list of SIOC enabled sites with the SIOC Firefox plugin and didn't really find any examples of interlinked communities or conversations. Am I missing something?
Here's a sampling of governance docs from some of Sun's many open source projects. I've listed them in order of what I feel to be, the most progressive (i.e. community governance) to least progressive (i.e. corporate control). I've also listed a key quote from each doc and made a brief comment about each.
Looks to me like the trend is towards community governance and the most important projects are the ones getting the most attention and the most progressive governance. That's good and I sincerely hope the trend continues.
After going missing in NB 5.5, Groovy support is back in Netbeans. Basic Groovy support with syntax coloring and support for running scripts from the IDE is available in plugin form (download page) for Netbeans 6.0 (starting with RC2), read about it on Geertjan's blog.
Here's what's coming after Netbeans 6.0, Groovy project support:>
After Netbeans 6.0, the story gets better. Geertjan writes that a brand new Groovy plugin will be available in the post-6.0 builds that adds support for three types of Groovy projects: applications, class libraries and Grails webapps.
I've got a couple of Roller related items to blog about, so why not just call it Roller Strong #11.
First, Lars Trieloff responds to some of the questions I raised about JCR and Roller in my ApacheCon wrap-up post. I left a comment on his blog in response. Personally, I think a JCR back-end is a very interesting idea and I wish I had some more time to explore it.
Manchi Leung AKA Thinkboy posted the code for a new Textile plugin to the Roller dev list, using Textile-J. Thinkboy says "it supports almost all of the Textile syntax. very much the same as Confluence wiki. Now I can easily sync or copy working notes from Confluence wiki to my personal Roller blog." Nice. Note to self: I need to fix up some of our existing entry plugins -- I think some of them (e.g. Ekit) still haven't been updated for Roller 3.1.
Arun Gupta blogged recently about Backing up your Roller entries and explained how to use the Grabber example (now known as BlogBackup in Blogapps 2) from the Blogapps project to backup your Roller blog. Backing-up your entries, but backing up your uploads is not. Hopefully, blogs.sun,com will turn on Atom protocol someday and that'll will make it easy for a tool like Grabber backup both entries and uploads.
We're still waiting on Roller 4.0, but I sense our wait is soon over. Roller 4.0 RC10 was released one week ago with just a couple of bug fixes. And so far, no critical issues have been found. We've got only one +1 vote (thanks Anil!) so far so committers please test and vote.
And finally, I have to mention MarkMail because I've been using it throughout this blog post. MarkMail provides a slick interface and excellent facilities for mailing lists of all kinds. They're indexing all of the Apache mailing lists and providing statis and charts for each. Check the Roller page at MarkMail for example.
That's all I've got for this go-round. Keep on rollin'
I just posted the slides for my ApacheCon US 2007 talk on the ApacheCon wiki. It's basically the same talk that I gave at ApacheCon EU earlier this year, but I spent some time tweaking the slides, simplifying removing unnecessary bits and adding a little Abdera coverage. That, and the fact that the power did not fail, seemed to make the talk go more smoothly this morning. Here are the slides: