We have just released Restlet 2.0 M3, replacing Restlet 1.2 M2 as our current “testing” release (following Debian terminology). We have also updated our “stable” branch with a 1.1.5 release.

Looking at the amount of new features that we added so far since Restlet 1.1 (with some more coming), the amount of refactoring and reorganization done on the Restlet API (including the core Resource API), on extension packages and with the growing number of special Restlet editions (Java SE/EE, Google Web Toolkit, Google App Engine and Android), it seemed appropriate to rename the Restlet 1.2 branch into Restlet 2.0.

Here is a summary of the main changes :

• New org.restlet.ext.xml extension including XML related classes previously in the core Restlet API. This ensures that the core Restlet API stays as consistent as possible across all editions. In this case, those features weren’t available in Android.
• Improved the org.restlet.ext.rdf extension with Turtle and N-Triples support in addition to RDF/XML and n3 formats.
• FreeMarker templates can now be loaded via the Context’s client dispatcher and relatively to a base URI.
• Added an org.restlet.ext.xstream extension providing transparent serialization between Java objects and XML or JSON.
• Added an ObjectRepresentation class to the GWT edition and to the org.restlet.ext.gwt server extension. This allows transparent serialization of Java objects leveraging GWT-RPC serialization mechanism, but using your REST APIs.
• Greatly improved the support for the recently added ConverterService.
• Improved the ClientResource with support for annotated interfaces via the creation of dynamic proxies. It now also automatically follows redirections when possible.
• Refactored the services to facilitate the addition of new ones by users in their applications.
• Added AppendableRepresentation for dynamic generation of StringRepresentation instances.

Direct contributors

• Arjohn Kampman
• Bruno Harbulot
• David Bordoley
• David Fogel
• Davide Angelocola
• Didier Girard
• Eric Hough
• Jean-Yves Cronier
• Lars Heuer
• Marcelo Ochoa
• Michael Berman
• Mikhail Spirydonau
• Paul Davis
• Rémi Dewitte
• Ronny Kwon
• Simon Reinhardt
• Tal Liron
• Thom Nelson
• Tim Peierls

Thanks to all others who helped us in various ways!

Additonal resources

Changes log:
http://www.restlet.org/documentation/2.0/changes

Download links:
http://www.restlet.org/downloads/2.0/restlet-2.0m3.zip
http://www.restlet.org/downloads/2.0/restlet-2.0m3.exe

Maven repositories:
http://maven.restlet.org is updated on the 1st and 15th of each month
http://maven.noelios.com is updated daily with new artifacts (access reserved to subscribers)

Our vision is that the Web is becoming ubiquitous and that REST, as the architecture style of the Web, helps you leverage all HTTP features. Restlet, our open source REST framework, is already available on regular computers based on Java SE/EE, in Web browers with our GWT edition and even in the cloud with a new Google AppEngine edition. But, we are still missing the Mobile Web!

With the commodification of smartphones started by the Palm Treo and pushed further by the Apple iPhone, more and more mobile users will have a usable access to the Web from their phone. So far, developers have been stuck with proprietary platforms and where lacking the productivity and portability common in the Java world. But here comes Android!

Android is an open source mobile operating system initiated by Google but now managed by the Open Handset Alliance. This consortium includes prestigious constructors such as HTC, Motorola, Samsung or Sony Ericsson and larger carriers such as Sprint, T-Mobile or Vodaphone. Needless to say that Android has gained a lot of traction recently.

Technically speaking, Android is built on a customized Linux kernel, libraries such as WebKit for the Web browser  and an extensible Application Framework developed in the Java language but running on a special Dalvik virtual machine (see a complete overview here). All the built-in applications are written in Java and can accessed or customized via an Android API.

Preparing for an imminent launch of the Android-powered HTC Magic phone in France (also known as the “G2″), the mobile operator SFR, one of the third largest in France, has announced a contest for the best Android application. We thought it was a perfect opportunity to port the Restlet framework to another exciting environment and applied as a “Restlet+FOAF” project.

With some adjustments (see technical details), we were able to port Restlet on Android, with both the client-side and the server-side HTTP connectors! To show the potential of Restlet on Android, we decided to go further and develop a simple extension to the Contacts applications that would retrieve the FOAF (Friend-Of-A-Friend) profile of your contacts, show their friends and let you add some as new local contacts. The source code of this sample application is available and documented in the Restlet User Guide.

With the help of Manning’s “Unlocking Android” book, we also discovered Android’s Intent/Service design pattern, which is quite similar to Eclipse’s plug-ins. This is a powerful way to extend Android applications and share common features. In our case, we developed a FOAF Service that can be reused by other Android applications, without tight coupling on our code.

Finally, with the growing number of Restlet editions, we felt the need to put in place an automatic porting process to keep the code changes synchronized. This effort is underway but you can already read its specifications in our developers wiki. All those new features are available in recent Restlet snapshots. Enjoy!

Update: On May 13, the jury of the SFR-Android contest selected our Restlet project for a special open source prize! Thierry is now the happy owner of a HTC Magic phone

We are living exciting times! This week, Google has released an early version of their widely expected support for Java in Google App Engine (GAE).

GAE is a computing platform that can host your Web applications and offer them  massive and flexible scalability. Free accounts are available and you can pay for extra resources (CPU time, bandwidth, storage and mails sent).

Of course, REST is the perfect choice to build your Web applications that will live in the Google cloud. But, GAE achievements come with constraints because you share computing resources with others. So GAE makes you live in a sandbox with a limited set of Java APIs.

The great news is that Restlet has just been adapted to fully work with GAE! This port provides in a single “org.restlet.gar.jar” file:

• Full Restlet API
• HTTP(S) server via the built-in Servlet adapter
• HTTP(S) client via the built-in adapter to java.net.HTTPUrlConnection
• SMTP client via the built-in adapter for JavaMail
• Server-side GWT support via the built-in GwtShellServletWrapper class.

In addition, support for GWT is available in both GAE and Restlet (see this post on our port of Restlet on GWT). The usage instructions are available in our online User Guide.

Google France provided us the early access to GAE after their launch event in Paris last Thursday, in collaboration with Didier Girard, Technical Director at SFEIR and author of the OnGWT web site.

Thanks to all of them and to Guillaume Laforge (who ported Groovy to GAE) for their advices and help making this port a reality so quickly and for sharing their passion for GAE!

This post isn’t an April Fools’ Day joke! We did released Restlet 1.2 M2 today including major enhancements:

Resource API refactoring

After a long experience with our class-driven Resource API introduced in Restlet 1.0 and the recent introduction of the annotation-driven JAX-RS API (that we support as a special Restlet extension), we felt it was time for us to step-back and propose a better solution, taking the best of both experiences.

We initiated a specification effort in our developers wiki at the beginning of this year, taking into account all the enhancement requests, issues and feed-back made by our community (with a special mention to Tim Peierls). Then, we analyzed those requirements and developped a first implementation for Restlet 1.2 M2. Here is the overall architecture:

The new design uses three foundation classes (UniformResource, ClientResource and ServerResource) which support just four annotations by default: @Get, @Post, @Put and @Delete. New ones can be defined to support extension methods like @Copy and @Move for WebDAV. Note that the support for annotations can be turned off and is not necessary to develop resources.

This new design provides the best of both worlds, the power and flexibility of Restlet 1.1 and the expressivity and additional abstraction offered by JAX-RS. In addition, it goes beyond those existing APIs by offering a uniform support for both server and client resources !

We look forward to your feed-back in order to complete and fully stabilize this work. We have started the adaptation of our traditional first steps, first resource and tutorial documents. It should give you a feeling of how it will simplify your Restlet developments.

RDF extension added

After a specification and design effort initiated for Restlet 1.2 M1, we now have a first usable version of our RDF extension. This extension contains a full RDF API, leveraging the Restlet API, and capable of processing RDF documents either in a DOM-like way or in a SAX-like way.

It is also capable of writing large RDF documents is a SAX-like way. We currently support two serialization formats: RDF/XML and RDF/n3. In the next version we will extend those formats to Turtle and NTriples. We will write later about the potential of the REST and RDF combination !

Security API refactoring

Thanks to a strong collaboration with our community, the new security API introduced in 1.2 M1 has been significantly improved and refactored. We have added support for Roles, Realms and Permissions with a better separation of concern between Components and Applications.

The API was deeply refined and now offers a good foundation for your new security efforts. We will focus on its stabilization and testing in the coming months. If you hadn’t have a chance to look at this effort yet, it is still time to influence its design while before we release the first 1.2 RC version which will freeze the API.

New Script extension

A very complete and powerful Script extension has been contributed by Tal Liron. It allows you to write Restlet resources and dynamic representations in the following script languages: Groovy, Jython, JRuby and PHP thanks to the standard “javax.script” facility and to Three Crickets’s Scripturian library.

This extension has been specified in detailled and has a very complete user documentation as well. Some additional work is planned to adjust it to the new resource API presented above, but we encourage all interested users to start playing with it and to provide feed-back.

The potential for this Script extension is huge as it will let us offer Restlet distributions dedicated to those scripting languages and broaden the usage of Restlet with developers not familiar with Java. Thanks again Tal for your hard work and for this wonderful contribution !

Enhanced Maven support

A long time ago, we offered a Maven distribution via our own Maven repositories and regularly we try to improve its quality, for example working with Buckminster users to adjust our Maven metadata. However, we use a custom forge based on Ant as our official build system and this has been causing some pains to Maven developers and putting some barriers for potential contributors.

Thanks to ideas and contributions from the community, we are now providing Maven POM files in our SVN repository as an alternative way to build Restlet. Of course, those POM files are the same that are distributed in our Maven repository and are consistently synchronized with our main Ant script to ensure that they don’t diverge in term of dependency versions for example.

For details on building Restlet with Maven, please read this short page on our developers wiki. Note that we have also adjusted our Maven GroupId (only “org.restlet” is used now) are redistributed third-party libraries are now packaged with a “org.restlet.lib.” ArtifactId prefix.

Package restructuring

In order to ensure a cleaner separation between resource and representation artifacts, we have added a new “org.restlet.representation” package and moved all representation classes to it. The “org.restlet.resource” package is now more focused, allowing us to welcome our new resource API and to move in related classes such as Finder and Handler.

We have also added a “org.restlet.routing” package where we moved Filter, Redirector and Router related classes. We plan to refactor the Route class for more extensibility. We encourage you to have a look at the new API as soon as possible to get familiar with it and anticipate the migration of your existing applications when Restlet 1.2 is stable.

When you upgrade, your existing code will look broken as many imports won’t be resolved. However, simply adjusting the package imports (using the dedicated feature of your IDE, like the “Organize Imports” feature in Eclipse) will fix all those issues. Indeed, the classes themselves have either not changed their API at all or have been properly deprecated.

Additional enhancements

But wait there is more! Many other valuable features were added in this release:

• JAX-RS extension now leverages the new Security API
• The TunnelService now supports “X-HTTP-Method-Override” header
• Client connectors for the ZIP and JAR pseudo-protocols were added
• The JsonRepresentation was improved (indentation, conversion)
• Microsoft Shared Key [Lite] HTTP authentication scheme supported
• Eclipse Public License 1.0 is an additional licensing option offered

Direct contributors

• Bruno Dumon
• Cliff Binstock
• David Fogel
• Fabrice Boileau
• Gordon Mohr
• Jean-Yves Cronier
• Jonathan Hall
• Kevin Conaway
• Lars Heuer
• Leigh Klotz
• Marcelo Ochoa
• Nels Nelson
• Niall Gallagher
• Paul Davis
• Raif S. Naffah
• Rémi Dewitte
• Rhett Sutphin
• Scooter Willis
• Sean Sullivan
• Tal Liron
• Tim Peierls

Thanks to all others who helped us in various ways!

Additonal resources

Changes log:
http://www.restlet.org/documentation/1.2/changes

Download links:
http://www.restlet.org/downloads/1.2/restlet-1.2m2.zip
http://www.restlet.org/downloads/1.2/restlet-1.2m2.exe

Maven repositories:
http://maven.restlet.org is updated on the 1st and 15th of each month
http://maven.noelios.com is updated daily with new artifacts (access reserved to subscribers)

After a long investment in WS-*/SOAP initiatives, Microsoft has recognized the value of REST. But they didn’t adopt REST only on the surface, they have put in place a comprehensive offer and are actively working to demonstrate and facilitate the interoperability with other platforms such as Java.

Silverlight

Facing a strong competition in the Rich Internet Application area, from Google with GWT, from Adobe with Flex/AIR/Flash and more recently from Sun with JavaFX/Applets, Microsoft has finally reacted with the introduction of their Silverlight 2 technology.

Silverlight requires a browser plug-in (ActiveX available for IE, Firefox and Safari) and provides you with a subset of the .NET Framework. Microsoft supports Windows and Mac while Novell has a Linux version called Moonlight. For the user interface it relies on a declarative language called XAML, not too different from Flex MXML or JavaFX scripts.

Regarding communication, it relies on WCF and offers direct support for HTTP/REST, RSS and Atom, POX/JSON and XML/LINQ. A description of the full architecture is available here.

Now, if you follow this blog, you are probably wondering how Silverlight interoperates with Java on the server-side. Even if its support for HTTP has a few limitations (partially due to its nature of browser plugin), Silverlight allows you to communicate easily with a REST back-end.

To demonstrates this, Microsoft has leveraged our Restlet framework and illustrated this interoperability with several detailled posts in their Silverlight plus Java blog written by Stève Sfartz from Microsoft. Other examples are available on Blog in the Cloud and Cloud it up.

eclipse4SL

If you are a traditional Microsoft developer, you would naturally turn to Visual Studio to develop your Silverlight applications, but what if you are a Java developer?

Well, Microsoft has done an unusual move by supporting the development of a Silverlight IDE for Eclipse! It’s called eclipse4SL and is co-developped with Soyatec, a French software editor specialized in Eclipse products development.

REST interoperability is also covered in eclipse4SL’s user documentation, illustrated by the usage of Restlet on the server-side. See this page for Restlet guidance. This is currently based on Restlet 1.0 and a Tomcat deployment, but work is underway to upgrade to Restlet 1.1.

The eclipse4SL project has even been submitted to the Eclipse foundation. See this post from the executive director of the Eclipse foundation.

TechDays

After meeting with Stève Sfartz, who very enthusiastically introduced us to Microsoft projects for REST, cloud computing and RIA, we worked on a join presentation for the Microsoft TechDays in Paris.

The goal was to present interoperability scenarios around REST. Thierry Boileau did the presentation for Noelios Technologies. A detailled summary (in French) has been posted by Stève Sfartz on his blog.

This presentation gave us the opportunity to show case our recent support for the Shared Key HTTP authentication scheme. This protocol is similar to the one defined for Amazon S3 and allows you to access to Microsoft Azure Data Services from a Restlet Java client.

This new feature is available in recent snapshots of our future Restlet 1.2 release!

Update 1:  article from BetaNews covering Eclipse4SL and mentioning Restlet

Update 2: Stève Sfartz has posted a complete article on MSDN detailling the example showcased at the TechDays (in French), including downloadable source code.

Restlet 1.2 is on its way with a first milestone! Let’s review the main changes made since version 1.1…

Security refactoring

The refactoring of the Restlet security model has been the most requested change since the Restlet 1.0 release. Fortunately, after a long maturation period, it has finally made a huge step forward, materialized by the addition of an “org.restlet.security” package. The new design is the synthesis of many contributions and discussions from the community.

Therefore, I’d like to especially thank Bruno Harbulot, Stephan Koops, Rémi Dewitte, Raif S. Naffah, Rob Heittman, Roman Geus, Alex Horn and Rhett Sutphin for their precious help. We still have much work ahead to complete and fully implement the new design but there is now a good foundation for feed-back and contributions.

Packages restructuring

In order to simplify even more the learning and deployment of Restlet applications, the Restlet API and its implementation (ie. the Restlet Engine) have been merged into a single module (ie. JAR, bundle). All engine classes were moved to “org.restlet.engine“.

In addition, all extensions are now located under a “org.restlet.ext” root package. This means that all extensions previously under “com.noelios.restlet.ext” have been moved. Be careful as this will break existing applications relying on those packages. However, as all the classes are still present, the migration should be straightforward, especially if you use the auto-import feature of your IDE.

Note that the core Restlet API has not significantly changed itself, only a few extensions are affected and a couple of classes not typically used by Restlet application developers such as:

• org.restlet.util.Engine moved to org.restlet.engine.Engine
• org.restlet.util.Helper moved to org.restlet.engine.Helper
• org.restlet.util.ByteUtils moved to org.restlet.engine.io.ByteUtils
• org.restlet.util.DateUtils moved to org.restlet.engine.util.DateUtils

Note also, that there were two Spring extensions in Restlet 1.1. Now they are merged under the “org.restlet.ext.spring” extension, led by Rhett Sutphin.

Connector enhancements

Thanks to a contribution of Kevin Conaway, the internal HTTP client now supports the HTTPS protocol as well, with parameters to configure SSL.

In addition, a Lucene extension has been created to host the Solr client connector contributed by Rémi Dewitte who will lead this extension. There is also a TikaRepresentation available to leverage Lucene Tika subproject when extracting metadata from representations.

Semantic Web initial support

As announced last August when we presented the Restlet 1.2 roadmap, we want to make Restlet a great framework to build applications for the Semantic Web. The relationship between REST and RDF is perfect and builds around the concept of resources and their representations (REST) and the expression of meaningful links between those resources (RDF).

We have written a detailed specification and gathered feed-back from the community and especially Henry Story, an expert in this area.

In Restlet 1.2 M1, we have added Literal, Link,  LinkReference, LinkSet and RdfRepresentation classes. That makes it easy to build a RDF graph, like you would use a DOM API to build and XML document. We now have to develop the serialization and deserialization logic during the next milestone for formats like RDF/XML and RDF/n3.

Direct contributors

• Ben Johnson
• Charles Gay
• Cliff Binstock
• Cliff Binstock
• Daniel Woo
• Eirik Bjorsnos
• Frank Hellwig
• John D. Mitchell
• Jonas Maturana Larsen
• Kevin Conaway
• Nicolas Rinaudo
• Remi Dewitte
• Rob Heittman

Thanks for all others who helped us supporting the community in the discussion list!

Additonal resources

Changes log:
http://www.restlet.org/documentation/1.2/changes

Download links:
http://www.restlet.org/downloads/1.2/restlet-1.2m1.zip
http://www.restlet.org/downloads/1.2/restlet-1.2m1.exe

Maven repositories:
http://maven.restlet.org is updated on the 1st and 15th of each month
http://maven.noelios.com is updated daily with new artifacts (access reserved to subscribers)

Last year, MuleSource released RESTpack, an extension for their leading open source Mule ESB product. This pack has just been updated and now includes support for the latest Restlet 1.1 version.

The Restlet transport provides  a deep integration, both on the server and the client side, between Restlet and Mule ESB. For more information, you can read the dedicated documentation page.

We had the opportunity to talk with Dan Diephouse, the software architect and REST expert who is leading this effort.

We asked him what are the benefits that Mule RESTpack and Restlet transport bring to existing Restlet users and, more generally, how do ESB and REST fit together conceptually?

The big benefit is that you can start to build integration applications that not only utilize RESTful HTTP services, but JMS, email, BPM, etc. In addition to just hosting Restlet services in a container like fashion, you can do things like:

• Route messages to different services and transports (e.g. using URI templates to route to different JMS queues)
• Kick of other process flows when an HTTP Response is sent
• Utilize all the built in capabilities for transformations, routing, and message filtering that Mule has to offer.

If you are looking for an ESB solution with strong REST support, this is a great opportunity to leverage two mature open source technologies. We already had a report of a successful usage of Restlet with Mule ESB in a large project in France!

On the French IT market, Octo Technology is a top consulting company, specialized in software architecture. Since its creation in 1998, it has regularly shaped the technology landscape through their famous white papers.

In 2007, they showed a clear understanding of REST by publishing “Web Services: Architectural Choices” (in French) by Philippe Mougin. The latest in the series is  a “Java Productivity Primer” (in English) detailing “Twelve guidelines to boost your productivity with a software factory”.

In their first guideline, “Adopt a productive Java platform that’s tailored for your project(s)”, they warn against bloated commercial platforms and propose an example of a state-of-the-art, low-cost Java platform which includes Restlet to develop their Web services.

They say they really like Restlet because the “framework is built for the REST architectural style, which is HTTP’s native architectural style. It lets you leverage the Web’s intrinsic qualities (scalability, loose coupling, etc.) much better than RPC- and/or SOAP-oriented frameworks”.

PS: Thanks to Charles Gay, from jGuard, for first pointing me to this document.

Update 1: See related blog post from Philippe Mougin

On the 4th of November, I presented a session on REST, Restlet and our port to GWT at the local JUG (Paris Java User Group). More than 200 juggers attended, with a first part on GWT presented by Didier Girard, from onGWT.

Eric Le Merdy, from Valtech, very creatively illustrated the presentation. Here is our first Restlet cartoon!

Thanks to Antonio Goncalves, David Dewalle and Zouheir Cad, the co-founders of Paris JUG for organizing this event. Keep up the fun, the passion and the professionalism!

Here are additional links about the event (all in French):

• Interview by Thomas Queste
• Summary by Anthony Dahan
• Summary by Fabien Duminy
• Summary by Nicolas Martignole
• Paris JUG session page

Since the launch of Restlet 1.0 in April 2007, we have been working hard to prepare this new version. To protect your investment in existing code, we have maintained the initial API design, extending it where necessary and always ensuring a direct if not transparent migration path.

Here is a selection of the most exciting new features:

• Broader and deeper HTTP support with features such as partial downloads, resumable uploads or content integrity validation.
• Best support for the WADL specification in the industry, allowing an automatic and always in sync documentation of your REST APIs. WADL documents can be generated in XML or converted on the fly to HTML using the popular stylesheet from Yahoo!
• One of the first and most complete implementations of the new JAX-RS 1.0 specification provided for those preferring an annotation-oriented approach.
• New Restlet-GWT module provided, porting the client-side of the Restlet API to the popular Google Web Toolkit 1.5 JavaScript platform, allowing you to invoke RESTful applications right from your Web browser.
• New extensions for easier integration with the JAXB 2.1, JiBX 1.1, Spring 2.5, OAuth, OSGi, Oracle XDB and SSL technologies.
• Improved support for Atom Syndication XML format and for Atom Publishing Protocol. Both formatting and parsing are now available.
• New POP3 connector based on JavaMail to access RESTfully to remote mail boxes.
• New Grizzly HTTP server connector, first to fully leverage the NIO support in the Restlet API, leading to new levels of scalability and performance.
• New internal HTTP client and server connectors to simplify development phases (zero configuration necessary) and allow very small footprint deployments.

In addition, we have significantly expanded our documentation with a 150 pages long Restlet User Guide, a screencast and first steps tutorials. We have also added new licensing options: LGPL 3.0 and transferable commercial licences (OEM).

You just need to download Restlet 1.1.0 to enjoy those new features !

Update 1: Launch coverage

• Artima – Developer Spotlight Forum
• Developpez.com – Article in Java blog (French)
• François Goldgewicht – Opinion on Restlet 1.1 launch (French)
• Iam Keke – Opinion of on Restlet 1.1 and Restlet-GWT module
• InfoQ – Restlet 1.1.0: Improved Flexibility and Specification Support (with interview)
• ITR Manager – Le logiciel RESTLET passe en version 1.1 (French)
• JAXenter – Restlet 1.1 veröffentlicht (German)
• PROgrammez! – News coverage on Restlet 1.1 (French)
• The Server Side – Discussion on Restlet 1.1
• Xebia – Plus de souplesse et une implémentation de JAX-RS 1.0 (French)

Update 2: Migration guide from Restlet 1.0 to 1.1