It is our pleasure to announce that the long-awaited final release of the Spring Framework version 2.0 is now available.

Download | Documentation | Changelog 

As the leading full-stack Java/Java EE application framework, Spring delivers significant benefits for many projects, reducing development effort and costs while improving test coverage and quality.

This stable, production-grade release comes after 9 months of active development.  In this short time the Spring 2.x series has matured immensely, benefiting from over 150,000 early access downloads across 9 milestone releases, resulting in over 750 JIRA issues resolved, 50 of which introduce major new features.

What's New?

We believe three attributes capture what our users can expect from the Spring 2.0 series: Simple, Powerful, and Proven.

Version 2.0 brings major new simplifications to the framework's overall usage model.  As our existing users know, the heart of Spring is the Bean Container which drives the configuration of your Java and Java EE application.  In version 2.0 many common configuration tasks have been simplified through the introduction of custom Bean Configuration Dialects.  What does this mean to you?

This means you can now:

• Make your business services transactional in one-line of configuration code.
  
• Lookup objects from JNDI in one-line of configuration code.
  
• Expose externalized properties to your services in one line of configuration code.
  
• Apply consistent exception handling policies to your data access objects with a single annotation.
  
• Invoke Stateless Remote EJBs by defining a single configuration tag.  No more custom service locators or business delegates.
  

• Write parameterized JDBC queries in one line of code.
  
• Apply convention over configuration when deploying your Spring MVC controllers.
  
• Use Spring JSP tags to reduce your typing when developing input forms.
  

A major goal of Spring 2.0 is to make the common tasks easier.  Version 2.0 also opens up exciting new doors for solving the harder problems in an elegant manner.  In 2.0 you may:

• Weave custom behavior into multiple points of program execution using AspectJ's concise pointcut expression language.
  
• Receive asynchronous JMS messages with transactional and thread-safety guarantees.  See it live
• Develop your own Bean Configuration Dialect for your application.
  
• Inject objects from custom scopes such as "request" and "session" scope in a thread-safe manner.
  
• Invoke Groovy, Beanshell, and JRuby scripts from your Java application.
  
• Schedule tasks to run asynchronously with sophisticated threading and pooling options.
  

Version 2.0 builds on the foundation set by Spring 1.x.  This new release delivers major new functionality while preserving backwards compatability as far as possible.

With over one million downloads since its release in March 2004, Spring 1.x made developing sophisticated applications from plain Java Objects (POJOs) the de-facto standard.  The 2.x series builds on this widely-recognized best-practice to deliver new simplification and power while preserving full compatiblity with the established Spring 1.x series.  Users can expect their upgrade to be straightforward; in most cases, simply a matter of replacing the 1.2.8 JAR files with those included in Spring 2.0.

Enjoy, and thank you

Spring 2.0 represents the cumulative effort of many over the last year.  From the lead developers Juergen, Rob, Rick, and Costin at Interface21, to our supporting partners BEA and Oracle, to the many in the community contributing innovations, patches, documentation, bug reports, and tests--there is a lot of blood, sweat, and tears here.  We truly hope you find this new version as much a joy to use as it was for us to build.  Enjoy, and rest assured: the work doesn't stop here.

Sincerely,

The Spring Team

Additional Resources

• Watch Juergen and Rob's interview with InfoQ on the goals of Spring 2.0.

• Attend The Spring Experience 2006, the premier conference for the Spring community, December 7th - 10th in Hollywood, Florida.  Register by October 16th to secure the early bird discount for your team.

• Get started with Spring 2.0 by downloading the release and reviewing the JPetStore and Petclinic sample applications, supplementing with the reference manual and API JavaDocs as needed.

• Get community support at forum.springframework.org.

• Read content leading up to the release including the Spring 2.0 update and Adrian's Simplifying Enterprise Applications.
  

• Track future Spring 2.x development with the Roadmap

• Get insights from the leads of Spring development at the Interface21 team blog.

• Interface21 is offering upcoming and newly updated Spring 2.0 training courses in 2006 and 2007.

• Spring 2.0 will be available in the Maven2 repository in the coming days.
  

• The release of Spring Web Flow 1.0 final will follow next week.

• Bookmark this page for the rollout of additional screencasts and code examples showing the new 2.0 features in action.
  

It is a common misconception that I hear when talking with clients that all information about generic types is erased from your Java class files. This is entirely untrue. All static generic information is maintained, and only generic information about individual instances is erased. So if I have a class Foo that implements List<String>, then I can determine that Foo implements the List interface parameterised by String at runtime. However, if I instantiate an instance of ArrayList<String> at runtime, I cannot take that instance and determine its concrete type parameter (I can determine that ArrayList requires type parameters). In this entry I’m going to show you a practical usage for some of the available generics metadata that simplifies the creation of strategy interfaces and implementations that differ by the type of object they process.

A pattern that I see occurring in many applications is the use of some kind of strategy interface with concrete implementations each of which handles a particular input type. For example, consider a simple scenario from the investment banking world. Any publicly traded company can issue Corporate Actions that bring about an actual change to their stock. A key example of this is a dividend payment which pays out a certain amount of cash, stock or property per shared to all shareholders. Within an investment bank, receiving notification of these events and calculating the resultant entitlements is very important in order to keep trading books up to date with the correct stock and cash values.

As a concrete example of this, consider BigBank which holds 1,200,000 IBM stock. IBM decides to issue a dividend paying $0.02 per share. As a result, BigBank needs to receive notification of the dividend action and, at the appropriate point in time, update their trading books to reflect the additional $24,000 of cash available.

The calculation of entitlement will differ greatly depending on which type of Corporate Action is being performed. For example, a merger will most likely result in the loss of stock in one company and the gain of stock in another.

If we think about how this might look in a Java application we could assume to see something like this (heavily simplified) example:

public class CorporateActionEventProcessor {

    public void onCorporateActionEvent(CorporateActionEvent event) {
        // do we have any stock for this security?

        // if so calculate our entitlements
    }
}

Notifications about events probably come in via a number of mechanisms from external parties and then get sent to this CorporateActionEventProcessor class. The CorporateActionEvent interface might be realised via a number of concrete classes:

public class DividendCorporateActionEvent implements CorporateActionEvent {

    private PayoutType payoutType;
    private BigDecimal ratioPerShare;

    // ...
}

public class MergerCorporateActionEvent implements CorporateActionEvent {

    private String currentIsin; // security we currently hold
    private String newIsin; // security we get
    private BigDecimal…

I am very excited to announce that the Spring SIG within the New England Java Users Group will be having our first meeting this Thursday (September 28th, 2006). Ramnivas Laddad (author of AspectJ in Action and Interface21 Principal) will be presenting "AspectJ for Spring Developers". This will be a great chance to learn about the enhancements in AspectJ integration within Spring 2.0.

You can read the details HERE, and be sure to click on the 'Register' link on the left-hand side of the page if you plan on attending.

This group will provide a great forum for "all things Spring" and will be meeting roughly once per quarter initially. I am looking forward to building a community and personally meeting fellow Spring users in the greater Boston area.

A special thanks to NEJUG president Steven Maienza and the NEJUG members who expressed an interest in having a Spring group and put this into motion before I even moved to Boston. Thanks!

A couple of weeks ago, the Spring Framework project passed 1 million downloads from its home on SourceForge. The true total is probably much higher, as this figure does not include nightly builds or the other sites from which Spring can be downloaded. And, of course, Spring is included in the distributions of a large and growing range of other products. And then there's Spring.NET...

Most important, Spring continues to gain momentum: the numbers are growing very rapidly. The most downloaded version of Spring is the most recent production release, 1.2.8, which has been downloaded 175,000 times…

Welcome to my new blog! I haven't blogged since August 2004, but have been inspired by our new team blog to try to lift my game. I've also been shamed by the blog-energy of my colleagues.

I'm very excited about a lot of topics at the moment, and promise to blog much more often than once every 2 years in future... Stay tuned for my thoughts about Spring 2.0 and beyond, OO design, AOP, and the future of enterprise Java.

In the meantime, I'll share my travel schedule for the next few months (which will at least give me an excuse for not always posting regularly):

• October 1-6: JAOO conference in Aarhus, Denmark.
• October 10-11: BEAWorld event in Prague. Always a beautiful city, although Prague is no longer a cheap destination.
• October 23: Keynote about Spring 2.0 at the Oracle Develop event, a new part of Oracle Open World conference, in San Francisco. This looks set to be a big conference.
• November: I'm spending most of November in Australia, partly to visit family and friends, and partly because Interface21 has opened a new office there, headed by Ben Alex, Acegi Security lead. I'll be speaking at various events, including Spring User Groups in Sydney and Brisbane, the Sydney JUG, and a forum in Melbourne.
• November 27-28: JAX Asia conference in Singapore. This is a new conference. The German JAX conferences are big and have interesting content, so I'm looking forward to it. With amazing timing, this is just at the time I was returning to London from Sydney, so I'm literally in the area... There's also a JAX conference in Jakarta, but I'm at the limit of my travel tolerance for the next few months already and just couldn't commit to that.
• December 7-10: This is going to be the most fun. The Spring Experience, in Hollywood, Florida. This year we expect over 500 developers, and great speakers as usual. Keith is doing a great job of organizing it, along with Jay Zimmerman of No Fluff Just Stuff fame.
• 11-15 December: JavaPolis in Antwerp. A big European conference, great value for attendees and always has a top speaker lineup--probably because organizer Stephan Janssen seems to know everyone who's anyone in the Java community. And of course Belgium is always worth visiting, if only for the beer. I'm a big fan of Belgian white beer in particular.

There has been quite a bit of discussion over my recent announcement about Spring and Maven. The discussion is all very good and worthwhile, but I do want to clarify a couple of points that I made.

First and foremost, we are committed to supporting Spring users who are using Maven as their build system of choice. This means we will help ensure accurate POMs are available in the Maven repository with each Spring release starting with Spring 2.0 RC4. That is what the world's most most popular JIRA issue is all about. Nothing more.

The topic of Spring's own internal build system is a…

Spring Framework 2.0 RC4 has been released. This is the last release candidate before Spring 2.0 final, and you may find out more about it from the release announcement itself as well as the JIRA issue list for a complete list of changes in this release.

Possibly the most important thing to watch out for is that this release introduces versioned file/location names for the 2.0 DTD and Schemas (XSDs). This was necessary since the XML bean definition format was significantly enahnced for 2.0, but 1.2.x users still need to be able to refer to the 1.2.8 DTD. Here is an example of using the 2.0 "beans" schema (2.0 ships with a number of other new schemas as well, representing various special namespaces…

We are pleased to announce that Spring 2.0 RC4 has been released.  Download | Documentation | Changelog

This is the last release candidate before Spring 2.0 final.  RC4 includes many further bug fixes and refinements in various areas, as well as minor new features (for example in the JMS support). Please see the changelog and JIRA issue list for all the details.  The most notable changes include...

New and Noteworthy

• This release introduces versioned file names for the 2.0 DTD and XSDs. Please adapt your bean definition files if they build on the 2.0 XSDs on or 2.0-specific DTD features.  For example:
  

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            xsi:schemaLocation="
                http://www.springframework.org/schema/beans
                http://www.springframework.org/schema/beans/spring-beans-2.0.xsd">

    <!-- Define your beans here -->

</beans>

• As you would expect, the Spring 1.2 DTD is still fully supported under its established spring-beans DTD file name.

• 2.0 XML configuration elements and attributes are now fully documented for each schema we support.  Special thanks to Rick Evans for his contribution in this area.
  

• Apache OJB support (org.springframework.orm.ojb) is no longer shipped with the core Spring distribution as of this release. It is now available from the Spring Modules project.

• Spring's JPA support is now fully tested against Oracle TopLink Essentials v2 b16 as well as Hibernate EntityManager 3.2.0 CR2. Our extensive integration test suite fully passes for both of those JPA providers now. We are currently in the process of covering OpenJPA in the same fashion.
  

We look forward to your feedback on this release.

Enjoy,

Juergen Hoeller
Lead of Spring Framework Development

Can you guess what it is? If you guessed a Maven bundle/build for Spring you win. Come see me at The Spring Experience in December and we'll share a frosty beverage as your prize.

Mea Culpa

Status

That said, it's not quite time for celebration. Converting the last two projects (Spring and Spring Web Flow) are non-trivial tasks (just take a look at Better Builds with Maven if you don't believe me). As such, the conversion is not something that we really want to do this close to the major 2.0 and 1.0 releases. What I can tell you is that the conversion is a goal scheduled for after the releases.

So what's the plan?

Then what can I, the user, do in the meantime?

Anything else you want to know about?