As most of you know, one of the big improvements in Spring 2.0 is the addition of the AspectJ pointcut language and better integration with AspectJ in general. While I think everyone believes that this will be a great benefit in the long run, it has led to some issues. We've found that there are certain behaviors that Spring AOP has always done, that AspectJ has never done.

One of the big issues that cropped up was the behavior of Before advice. If you've used Spring AOP in Spring 1.x you probably know that Spring allows you to change argument values before they are passed to the target…

Spring - here to stay for a long time I visit many clients and speak to even more on a day-to-day basis. This includes existing Interface21 clients as well as companies that are interested in our products and services across Europe. I have noticed a recurring theme in the conversations I am having: Spring is here, and it is here to stay.

Over the last year I have witnessed executive-level decisions that have standardized Spring throughout the fabric of leading Enterprise Java development firms. Just two weeks ago I asked one of my clients - a Java unit manager at one of Europe's largest…

Lately it seems like I've been focusing on creating Spring XML namespaces. It's been a lot of trial and error (both on the XSD and Spring side) to get a good pattern for creating parsers. One of the biggest confusions that I ran into was the AbstractBeanDefinitionParser hierarchy. At this point it isn't documented especially well (but there is a JIRA for it, so it'll be fixed before GA), so I'll give you a rundown of your choices, what they're good for and how to use them.

AbstractBeanDefinitionParser choices

• AbstractBeanDefinitionParser
  • AbstractSingleBeanDefinitionParser
    • AbstractSimpleBeanDefinitionParser

I'm going to start at the most specific and work towards the most general to show how to gain more power when you need it. If you want to skip the examples and see the summary, check here…

Hey all!

This is my first post since I joined Interface21 last month. My previous blog is now officially deprecated and I won't be updating it anymore.

So what is the subject of my first post (except to introduce myself)?  Validation logic.  It won't be a walkthrough of how to perform validation in the Spring framework, rather it will discuss a particular bug bear of mine :)

In particular, I would like to discuss exactly what should go into validation logic.  It seems to be a no-brainer answer; "logic to validate the specified data".  OK, that is a no-brainer but read on :). As you know, the Spring framework provides a nice abstraction layer for your validation, via the Errors and Validator interfaces.  In particular the Validator is where you apply your business specific validation rules to your populated domain object.  Spring's excellent binding support is responsible for updating your domain model…

Hello all,

This is just a quick entry to let you know I have officially relocated my biz.blog to here, our new Interface21 team blog.  I'm excited about this group blog serving as the voice of Interface21.  For those of you who know me, you know to expect a different perspective.

I have got some saved drafts I am working on. Watch for new entries that provide insight into the business aspects of Interface21 soon...

Until then, Steven

Of all the new Spring 2.0 features and improvements, I must admit that Message-Driven POJOs are one of my personal favorites. I have a feeling that a lot of other Spring users will feel the same way.

Here I am providing a quick introduction. There is a lot more to show, and I will follow this up with other posts. For now though - this should provide you with enough information to get up and running with some truly POJO-based asynchronous JMS! I hope you are as excited about that as I am ;)

Prerequisites:

You will need the following JAR files on your classpath. I've also listed the versions that I am using (any spring-2.x version should be fine. I just dropped RC3 in there about 2 minutes ago in fact):

• activemq-core-3.2.2.jar
• concurrent-1.3.4.jar
• geronimo-spec-j2ee-managment-1.0-rc4.jar
• commmons-logging-1.0.4.jar
• log4j-1.2.9.jar
• jms-1.1.jar
• spring-2.0-rc3.jar

Setup the Environment

First, we need to setup the environment. I am going to be using ActiveMQ, but the impact of changing a provider will be limited to modifications within this one file. I'm calling this file "shared-context.xml" since as you will see shortly, I am going to be importing these bean definitions for both sides of the JMS communication. Here are the "shared" bean definitions: the connection factory and two queues (one for the requests and one for replies):

<?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.xsd">
	
    <bean id="requestQueue" class="org.activemq.message.ActiveMQQueue">
        <constructor-arg value="requestQueue"/>
    </bean>
 
    <bean id="replyQueue" class="org.activemq.message.ActiveMQQueue">
        <constructor-arg value="replyQueue…

An article I wrote for the InfoQ site has just gone live: Simplifying Enterprise Applications With Spring 2.0 and AspectJ.

I've heard a number of people saying that "AOP is too hard", or "AOP makes things too complex". In a way this article was written as a rebuttal of those views (hence the title, "Simplifying Enterprise Application Development"). I mean, the whole point of AOP is that you take software that was getting complex and tangled up, and you simplify the implementation by giving each module a single responsiblity again by introducing aspects. And then of course for some…

Spring 2.0 has added support for the JPA data access standard with all of the standard Spring support classes one would expect. Mark Fisher has a great post on how to use this new support. However one of the questions that we keep getting is why one would want to use a Spring class (JpaTemplate) to access an EntityManager. The best answer for this question lies in the value add that JpaTemplate provides. In addition to providing the one-liner convenience methods that are a hallmark of Spring data access, it also provides automatic participation in transactions and translation from …

Yesterday there were a few posts related to the forthcoming Beginning Spring 2 book, and I wanted to point those out here.

First, since this book will be of interest to those new to Spring - or even those who are simply curious at this point, we decided that it would be a good idea to include some discussion of common misconceptions about Spring. These have been posted here:
http://www.oreillynet.com/onjava/blog/2006/08/ten_common_misconceptions_abou.html
and on the Apress blog: http://ablog.apress.com/?p=1221.

Second, Interface21's Steven Devijver, the book's tireless lead author, has posted a great overview:
http://blog.interface21.com/main/2006/08/03/finishing-beginning-spring-2-from-novice-to-professional/.

The book, Beginning Spring 2: from Novice to Professional, will be in stores this October. While it aims to provide a gentle introduction appropriate for new Spring users, it will also be very useful for "filling in the gaps" even if you have been using the Spring Framework for a while. In other words, the book covers a lot of ground: the Spring container, AOP, data acess, MVC, and more. The coverage includes many new Spring 2.0 features - most notably an entire chapter exploring Spring's new and improved approach to AOP such as the XSD-based AOP namespace, integration with the AspectJ pointcut expression language, and @AspectJ integration! (Don't worry Spring 2 is backwards compatible - and the migration path is easy too). Throughout, the book provides a pragmatic balance of theory and examples. Those examples are backed by an interesting sample application (not overly simplistic). I personally was delighted when Steven asked me to contribute some exercises - yet another of his great ideas for providing an excellent resource to beginners. The first set of exercises walk through several techniques of dependency injection from basic wiring to the use of FactoryBeans and externalizing properties files. The second set of exercises are focused on AOP - including the new namespace and the @AspectJ style.

We are looking forward to an active companion site after the book's release, and of course you can continue to find many great discussions and examples of Spring 2.0 features here at the Interface21 team blog.