Blogging Roller

There was quite a flurry of blogging about the Atom Publishing Protocol (APP) over the weekend, all kicked off by Dare Obasanjo's criticisms of the protocol. Some of the posts were critical of Dare and his motives, but I'm thankful he started the conversation. Here's the dump from my del.icio.us account:

• Dare Obasanjo: Why GData/APP Fails as a General Purpose Editing Protocol for the Web - Good only for microcontent, no support for partial updates, poor support for hierarchy and "we [Microsoft] will likely standardize on a different RESTful protocol"

• Bill de hÓra: APP on the Web has failed: miserably, utterly, and completely - APP editor Bill de hÓra responds to Dare's APP critique
  
  
• snellspace.com: Silly: James Snell responds to Dare's APP critique. Cites usage of APP in Lotus Connections.
  
  
• Joe Gregorio: In which we narrowly save Dare from inventing his own publishing protocol: APP editor Joe Gregorio's point-by-point response to Dare's APP criticisms
  
  
• David Megginson: REST, the lost update and the sneakernet test: - "Without exclusive locks, there’s no way to avoid this problem, but it is possible to detect it."
  
  
• Tim Bray: I’ve Seen This Movie: Tim Bray responds to Dare's post: "Microsoft has tried to swim against the current of the Internet a few times before"
  
  
• snellspace.com: Beyond APP - Partial updates: Dare's post inspires James to post a strawman proposal for using HTTP PATCH to implement partial updates w/Atom.
  
  
• Keith Fahlgren: Partial Updates, a simpler strawman: "The basic inspiration is thinking about each operation as an XSLT template"
  
  
• snellspace.com: Partial Updates in APP, Part 2: James responds to Keith's simpler strawman.
  
  
• Dare Obasanjo: GData isn't a Best Practice Implementation of the Atom Publishing Protocol: Dare responds to the flurry of APP posts he kicked off

A bunch of Atom and REST related links that I came across while catching up with my blog reading today:

Atom and LDAP sitting in a tree. Trey Drake has released his OpenDS based Atom store as an open source project on Java.net at http://atom.dev.java.net. It's a directory server distributed as a Java web application that supports both Atom Publishing Protocol (APP) and Lightweight Directory Access Protocol (LDAP).

Signing, encrypting and decrypting Atom. On IBM developerWorks, Nicolas Chase explains how "digital signatures and encryption can easily mesh with Atom data using the Apache Abdera API."

Google GData: A Uniform Web API for All Google Services. Dare Obasanjo praises Google for creating a single uniform and RESTful web services API for eight of its key services, the APP based GData API. He writes "not only is it now possible to create a single library that knows how to talk to all of Google's existing and future Web services since they all use GData. It is also a lot easier to provide 'tooling' for these services than it would be for Yahoo's family of Web services given that they use a simple and uniform interface."

RESTful web services support in Netbeans. Geertjan links to blog entries and a screen-cast that explain Netbeans 6.0 support for RESTful web services, including the early access JSR-311 REST API.

Generate code from your WADL REST API. Eduardo at The Aquarium links to Thomas Steiner who is making progress on a WADL editor and a generator, bringing WSDL-like code generation to RESTful web services.

Is it this http://cyber.law.harvard.edu/rss/rss.html, promoted by Dave Winer?

This http://www.rssboard.org/rss-specification, from the RSS advisory board?

Or one of the other dozen or so incompatible formats.

It doesn't really matter. There's only one Atom: RFC-4287.

Hat tip to Sam Ruby.

German Viscuso: Generally spoken GData provides a general interface to make information available even beyond a browser context by providing a single API that could be used to query, update, and index structured data anywhere on the web. Could GData become a simple and open replacement for all the proprietary communications protocols currently in use by database vendors?

Interesting thoughts. I've heard about the Atom Publishing Protocol (APP) based Lucene Web Services API, but I hadn't heard about the Apache Lucene GData server project. Atom protocol is moving fast, especially considering the fact that it's not finished.

As usual, I'm enjoying JavaOne and meeting lots of new people and putting faces to names. I've also been practicing my talk daily so I can give you my best performance, so eat lunch a little early or a little late and come see how it goes. Here are the details:

• TS-6029 - Beyond Blogging: Feeds in Action
• Friday 05/11/2007  12:10 PM -1:10 PM
• Moscone Center Esplanade 307 / 310

Trey Drake: How do you demo a directory server? Build cool apps around it. To that end, we've built an Atom/APP server, a lightweight OpenID server, a blogging and "twitter" like app - all powered by OpenDS. Drop by our booth (Glassfish alley at CommunityONE and .org section of the pavilion during JavaONE). Ludo and I will introduce OpenDS and show off the demos in two talks; today at CommunityONE at 5PM and Wednesday at 1:30 in the CommunityCorner.

Very cool. I'm not going to be the only one talking about Atom protocol at JavaOne. I'll have to stop by the CommunityCorner, that sounds too good to miss.

ROME Propono 0.5 is a minor bug fix release of Propono. You can get the release files and updated Javadocs from the Propono 0.5 release page.

Following up on the APP interop event last week, here are the ROME Propono APP client issues we found: 

• ROME #66 BUG - don't expect entry to be returned from update (FIXED)
• ROME #67 BUG - handle relative URIs in Service Doc
• ROME #68 BUG - handle out-of-line categories in Service Doc
• ROME #69 RFE - use pluggable auth. scheme w/Google and WSSE support
  

And here are the Roller APP server issues:

• ROL-1393 BUG - attributes in service doc should not be namespaced (FIXED)
• ROL-1394 BUG - wrong content-type for service doc (FIXED)
• ROL-1395 BUG - support slugs for entries too
• ROL-1396 RFE - RSD support, auto-discovery for APP
• ROL-1397 BUG - null byte 0x0 getting into entry contents

I plan on fixing the Roller issues for this summer's Roller 4.0 release. I won't have time to fix the Propono issues for the upcoming Propono 0.5 release (due this week), so they'll be in 0.6 sometime after JavaOne.

I was wondering what web services vendor WSO2 was doing at the APP interop event. Turns out, they've got a "Web Services Mashup Server" in the works.

The Atom Publishing Protocol interop event is over and now I'm catching up on blogs and email in my hotel room in Mountain View, CA. In the end, I was able to run ROME Propono successfully against Blogger/GData, AOL Journals and Wordpress. I also found a dozen small problems in Propono and in the Roller APP server.

For more information on the event, check O'Reilly's Keith Fahlgren's summary of the event titled Atom Publishing Protocol a Success. Keith mentions that "big industry players like AOL, Google, IBM, Microsoft, Oracle, and Sun are working on APP clients and servers and sent people to the interop event with interesting code" and I agree that's definitely a good sign for the protocol.

I thought it was particularly interesting that database vendors IBM and Oracle showed up with DB2 and Oracle-backed Atom stores. If Google's half-dozen or so Atom protocol based services aren't enough make you stand up and take notice, surely that should get your attention.

Day one of the Atom Publishing Protocol (APP) interop event was a success, at least from my point-of-view. I was able to test the Propono client against Blogger.com/GData, AOL Journals and an implementation from Oracle. I found and fixed problems in Roller's APP implementation. Plus, it was great to meet all of the good folks implementing Atom and to get a close look at the Google campus. I'm getting ready to drive back to Google now so... gotta go.

Check out Tim Bray's blog for some photos of the event.

I'm happy to announce the first release of the ROME subproject Propono. Propono is a ROME-based Java class library that supports publishing protocols, specifically the Atom Publishing Protocol and the legacy MetaWeblog API. Propono includes an Atom client library, an Atom server framework and a Blog client that supports both Atom protocol and the MetaWeblog API.

Here's the project page
  http://wiki.java.net/bin/view/Javawsxml/RomePropono

Here's the Propono 0.4 release page:
  http://wiki.java.net/bin/view/Javawsxml/RomeProponoRelease04

And here's a link to the API docs, which include details, diagrams and code examples:
  https://rome.dev.java.net/apidocs/subprojects/propono/0.4/overview-summary.html

I'll be testing Propono this week and next (at the Google-hosted APP interop meeting) so now is a great time to provide feedback and bug reports. I plan on releasing Propono 0.5 in the *very* near future.

We haven't released the standalone Roller-Planet application yet, but the .Sun Engineering team quietly deployed the latest bits at planet.sun.com a couple of weeks ago in response to requests from the Glassfish, SWDP and other teams for planet-style web sites. You can follow the links on the main page to find planets for Glassfish, SWDP, Sun India, Sun Alumni, Sun Java System Web Server, web services and globalization bloggers.

What's Roller-Planet? It's a community aggregation server, similar to Planet-Planet but with some key differences: it's got a web UI that enables groups of users to run their own planet sites, it's based on Java and it uses the ROME feed parser and fetcher. I've written about it before. We don't have a release plan yet for Roller-Planet so if you really want to try it you'll have to fetch and build it from the Apache Roller SVN repo.

I just got approval to attend the Atom protocol interop event at Google April 16 and 17. I'll be bringing at least three Atom protocol implementations: Roller's Atom server, Propono's simple file-based Atom server and Propono's Atom client.

I've heard the argument before that the REST approach to web services doesn't give you reliable messaging and that's the reason you need to stick with WS-*. Today Bill de hÓra disputes that notion with an interesting and somewhat provocative post that mentions a couple of specs for messaging via HTTP (HTTPLR and BTF) and argues that Atom protocol can serve as the basis for web-scale reliable messaging.

Bill de hÓra: There are a number of reasons to choose Atom Protocol as the substrate for web-scale reliable messaging. First, a ton of software will be written to target APP in the next few years, and there is plenty of scope for extending the protocol; this suggests openly available and flexible software stacks. Second, since all document collections in Atom Protocol are served as Atom Feeds, it has inherent support for systems management and end to end reconciliation. Third, Atom entries have identity and are natural envelopes, unlike SOAP, where identity and true enveloping requires further specification (essentially raw Atom presents a better basis for interoperation than raw SOAP). Fourth, Atom Protocol can support binary content transmission not just XML, and thus can transmit arbitrary payloads. Finally, because Atom Protocol respects media types and deployed HTTP infrastructure, independent proxy inspection and security check-pointing can be installed cleanly, also eliminating the need to rewrite 2 stack layers and buy XML appliances to support and secure SOAP backed web services. It seems to be a question of when, rather than if, this will get built out.

I would have blogged about this earlier today, but Bill's blog looked foobar and I didn't realize that today is CSS Naked Day. My blog doesn't look half bad naked.

As promised here's some more info on my JavaOne 2007 session. It's based in part on the Beyond Blogging presentation that I presented to a tiny audience at the local Tri-XML conference last year. Tim Bray didn't attend my talk, but he read the slides and called them "the single best introduction and overview I’ve ever seen about feeds and syndication and RSS and Atom and all that stuff." I shouldn't brag. Had he attended the talk he might have had an entirely different opinion, who knows. Anyhow, the presentation has been updated, stream-lined and large portions rewritten to cover ROME and ROME's new Propono sub-project. [Read More]

• David Van Couvering: Why use Atom Publishing Protocol for REST?
  "Why not just use HTTP and JSON and have done with it?"
• Max Ross: Ode to Hibernate (and Shards)
  "Shards, a framework that adds support for horizontal partitioning (or in Google parlance, "sharding") to Hibernate Core"
• James Snell: Don't Panic
  "it is possible to get very far with nothing but the base APP protocol."
• Elias Torres: Is AtomPP for or not for blogs?
  "we'll probably have to do some good amount of extra work in defining how blogging clients will interact with a blogging service"
• Rob Yates: Atom Publishing Protocol - not enough for blogs?
  Rob wants a guide that "allows blogging clients to be interoperable with blogging servers"
• Re: I-D ACTION:draft-ietf-atompub-protocol-14.txt
  Roy Fielding: "the sky is not falling, and AtomPP implementations will interoperate just fine"

Newsgator, makers of FeedDemon and NetNewsWire, have launched a Java ME powered RSS/Atom feed reader. Here are some details from the press release: 

NewsGator Go! for BlackBerry and NewsGator Go! for Java were developed in a technology partnership with FreeRange Communications, the leading developers of mobile publishing and mobile RSS solutions, and is available for BlackBerry, Sony Ericsson, Nokia, and most other MID-P 2.0 mobile phones, including Samsung, Sanyo and LG. NewsGator Go! is available for $29.95 or $14.95 if bought with any of NewsGator’s desktop readers, including FeedDemon, NetNewsWire and Inbox.

Via Randy Morin.

The Sun Web Developer Pack (SWDP) finally uncloaked today, so I can talk a little more openly about what I and my Java EE co-workers have been working on. You can get the full scoop at the SWDP site, but basically SWDP is a bundle of technologies to help developers build "Web 2.0" or next-generation web applications on the Java platform. Ajax, scripting languages, REST and of course RSS/Atom are all part of that. The RSS/Atom bits are ROME 0.9 (Beta), Blogapps 2.0 (Early Access) and a ROME-based Atom Server kit based on code from Roller.  There are also example Atom server implementations in the REST API and Phobos components of the pack.

I'm pretty excited that we're putting some resources behind ROME and that both ROME and Blogapps are part of SWDP R1, but I'm even more excited about the next release. In R2 we'll drop the Atom Server Kit and Blogapps BlogClient and we'll replace them with ROME Propono a brand new Atom protocol client and server library that we're getting ready to contribute to the ROME project.

I haven't had a whole lot of time to experiment with the various components in the pack, but I have played with Phobos and I think it's pretty compelling. Phobos is a "lightweight, scripting-friendly, web application environment." It's not just for creating server-side JavaScript applications, but that's the angle the I find interesting. So many developers are creating JavaScript/Ajax applications these days that working in JavaScript on both client and server-sides makes sense -- especially when you can debug into JavaScript code in your IDE as you can with the Netbeans Phobos module. Also note that the jMaki Ajax components work with JSP, PHP and Phobos -- jMaki and Phobos look like a winning combination.

 

I'm very happy to report that my talk was accepted for JavaOne 2007. I'll be giving a thoroughly revamped and updated version of my Beyond Blogging talk (aka Johnson on Feeds), which adds in-depth coverage of ROME and ROME Propono. I'm excited about going to JavaOne again, but I'm also feeling a bit frazzled. I'm swamped with work right now and I've got a stack of deadlines clustered around the March 20 due date for the slides.

I helped out with the session selection for the web-tier track this year so I can say with some confidence that at least one track is going to rock -- we've got a wonderful set of talks lined up, so don't miss it. The full session schedule isn't online yet, but registration is open.