techno.blog("Dion")

Brian McCallister wrote an interesting post (as per) explaining web containers.

One interesting point, is that although the topic is aimed at the Java spectrum, Brian uses Ruby as pseudocode in his tale.

The mix of Ruby/YAML is pretty clear, and does the job at getting the message across. This is because of the conciseness of the language. There is no extra crud that you have to put in there (static types, verbose APIs, etc).

So, if we want to write pseudocode in “language X”, I think that says a lot. Don’t we want our pseudocode to be as close to the metal as possible? Wouldn’t it be nice to take that pseudocode and just RUN it? We can :)

_why wrote about this too in Ruby as Coderspeak

The AspectWerkz team has released AspectWerkz 2.0 final.

AspectWerkz 2.0 final comes with bug fixes.

• option -keepjp renamed in -genjp (generate jit join points) (affects offline mode)
• perJVM mixin deployment-model restablished
• after returning advice was not handled properly in some cases
• issue with around advice and set() pointcut could happen with long/double fields
• issue with serialization and advised classes not implementing directly java.io.Serializable
• issue could happen when using hot re-deployment of advised J2EE applications

Read more and download

What’s new in 2.0

I was sitting in a session next to Adrian Colyer, and he showed me what he had literally just hacked up.

It is a nice proof of concept showing a DSL for event driven code.

It allows you to simply specify a publisher:

class Producer {
public Producer() {}

@RaisesEvent("price-update") private int price;

@RaisesEvent("calculation-complete")
public int calculate(int x, int y) {
return x*y;
}

public void setPrice(int price) {
this.price = price;
}
}

and a subscriber:

@EventSubscriber static class Recipient {

// exposed public fields for testing
public int calculationResult = 0;
public int price = 0;

@OnEvent("calculation-complete")
void onCalculationCompletion(MethodBasedEvent event) {
System.out.println("calculation-complete, result = "
+ event.getResult());
calculationResult = (Integer)event.getResult();
}

@OnEvent("price-update")
void onPriceUpdate(FieldBasedEvent event){
System.out.println("price-update, new price = "
+ event.getValue());
price = (Integer) event.getValue();
}
}

I hope that this could be firmed up, and maybe at some point make it into the ajlib project! :)

The old chestnut of “Java vs. .NET” has reared its head again (e.g. Java vs. Microsoft .Net debate rages).

I actually wished that one of the instant audience polls would have been:

How would like like TheServerSide to include other technologies outside of Java?

• Only Java Tech please! This is your niche! Have a TSS.NET conference for that stuff
• Other fringe tech, but from the point of view of an enterprise Java guy
• I have to work in a heterogenous environment, so would love a hard core .NET track. Besides. I don’t have to go :)

The reason I mention this, is that I think the community has chilled out from the days of “oh man, I hope .NET doesn’t take over!”.

Now, several years have passed, and J2EE is doing fine. .NET is doing fine too. We can live in harmony ;)

These days, a lot of developers work in the world of both Java and .NET. In fact, what does it even mean to be an “enterprise Java developer”.

Why, just today I wrote SQL, Java, JavaScript, ruby, Groovy, bash, and had to look at XML. Hardly Java only :)

Now the politics has died down, I think there is a lot to gain by having a conference where the camps mix. I enjoyed my time at MS Tech Ed last year, and learnt a few things.

Are we ready?

Justin Gehtland, co-author of Better, Faster, Lighter Java, has blogged about his experience porting an application running on a Java stack (Java/Spring/Hibernate/JSTL stack), to Ruby on Rails.

On speed of development

First of all, I

Ramnivas Laddad has got a two-part article series AOP and metadata: A perfect match, part of the AOP@Work series, in the queue.

He also talks about using annotations for compile-time, and strucural modifications to a program.

E.g., wouldn’t this be a nice way to simplify get/setters (a la Groovy):

public class Person {
@Property(ReadOnly) private long id;
@Property private String name;
}

It is going to be very interesting to see how these types of annotations get into the system. Will open source projects start building them? Will we wait for the JCP to standardize on them?

Adrian Colyer has taken Ramnivas’ idea and whipped it up using AOP (showing that you don’t need a custom APT (annotation processing tool)).

Since installing mt-scode for MoveableType, I wondered if there was a Java framework that would easily allow you to add CAPTCHA style authentication to our apps.

There is an open source framework: JCAPTCHA.

There is an article on the framework Use a CAPTCHA-based authentication module for J2EE Web applications

Spam has become one of the biggest menaces on the Web. Many community-based applications force authentication only to distinguish a valid user from an automated spam-bot, which can be overkill in some cases. CAPTCHAs help in differentiating between real users and automated bots. In this article, Anand Raman uses CAPTCHAs as weak authentication mechanisms for J2EE Web applications. He begins with a quick introduction to both the J2EE Web application security model and CAPTCHAs. He then builds on these concepts to implement a JAAS (Java Authentication and Authorization Service) login module using CAPTCHAs and integrates it with an application server’s existing security infrastructure. The artifacts are based on standard J2EE security mechanisms. Hence, the module can be reused on any J2EE application or across different application servers with some minor modifications.

We have been using Acegi security recently, rather than CMS, and it would be nice to plug this in over there.

I often worry about the images. On one site I had to reload 3 times to get an image in which I could actually read!

One of the controversial points of EJB 3, is whether it should be backwards compatible. The programming model is so different, that it hardly seems right to force 2.1 compliance, but rather, make that an option.

In fact, one of the instant poll questions at TheServerSide Symposium backed this up:

How do you think the EJB 3 spec should handle backwards compatibility (e.g. to allow for a Spring compliant version)

1) Make EJB 2.1 support and below MANDATORY
2) Make EJB 2.1 support and below OPTIONAL (a check box for vendors to compete)

The results came back as ~80% of the crowd wanting this to be optional. Linda DeMichiel mentioned on the panel that she did hear the community here, although I do realise that she has other groups wanting other things. Kudos to her for being the spec lead ;)

Many people at the show laid their point down:

Tim Dawson: Vendors don’t care that the spec enforces backwards compatibility, they care about which server vendors do!

Hear, hear,

We also know that many dev groups need to be able to say “I am using EJB compliant software”. This is from vendors to ISVs to large IT organizations. It is a reality. And, although a couple of vendors told me at the show:

Spring can support the EJB 3 annotations, so they will be source-code compliant…

I think this is short sited. You can’t say “Oh, well we aren’t EJB 3 certified, but we do grok it. Promise”.

So, what if the EJB spec does continue to enforce EJB 2.1 compatibility?

I am not as worried about this anymore. Of course, I would love to see the likes of Spring able to support EJB 3, but there is a good solution if it isn’t the case. Geronimo/Spring integration.

What if Geronimo had first class integration with Spring? Spring Beans/modules could automatically be loaded up with no need for anything else. There are many, many ways in which the two could integrate, and I have heard of some very exciting possibilities from the teams.

What this does, is that it changes the game. We can get the best of all worlds.

If you work in a place that requires “application servers” and the like, you can just use Geronimo for that need… which will be a fully compliant EJB 3, J2EE 5, server.

So, I predict that:

Geronimo will become the server to run the Spring framework within.

Imagine it! EJB 3 view on your Spring modules! No need for Spring to have to implement the spec at all!