Wednesday, August 28, 2002

Web services: Is it CORBA redux. Reasonable article covering some similar issues as one fell swoop. Though for me this article confuses 2 ideas a little but I guess thats for brevity. Whether a web service client or server views SOAP messages as an XML document, or whether it uses the WSDL definition to auto-bind it to objects, is up to it. Its one of the great things about SOAP, on the wire its just XML and its up to you how you deal with it. This article really seems to be claiming that RPC is not that scalable and that asynchronous web services is the way to go. I agree with this. The current batch of SOAP tools that auto-generate SOAP bindings from interfaces or EJBs or whatnot, typicaly make synchronous RPC web services and clients. Though there are times when RPC is necessary. Also an RPC can still use asynchronous processing. e.g. I may use a synchronous RPC web service to perform some banking operation, like transfer money. A good web service implementation would do as little work as possible synchronously, then do the rest asychronously, such as by sending a JMS message to an internal server to instruct more work to take place later on. So by using messaging, you can often make synchronous things more scalable and more asynchronous despite the RPC protocol. This trick usually works for writes or submitting operations and really doesn't work for queries if the client is synchronous. Finally going back to the paper one fell swoop, minimising the number of networking interactions is always a good thing. So sending things in one fell swoop, rather than than over lots of little conversations, can help greatly. Typically this kind of course grained messaging doesn't fit automatically with typical distributed object approaches which are based on fine grained (method call level) interactions. So I do favour taking a document centric approach to web services, and binding the documents to your objects, rather than just turning your objects, auto-magically, into web services. 6:44:05 PM    comment []

Is RedHat the Microsoft of Linux [Cafe au Lait]. A good read. 3:01:48 PM    comment []

A whisper of a hint of a light at the end of the IT spending tunnel. Aberdeen Research [The Register] A tad of good news... 1:06:48 PM    comment []

Swing and IDEs. I know this sounds lazy as hell, but SWING is a lot of freakin' work. I'm trying to create a log window in Java and I'm doing it using Swing and wow, there's just tons of options and details you have to look out for. Unlike web development, which is what I'm more accustomed to, doing real GUI development means you're in charge of the whole environment. Where the window appears, what happens when you resize, dialogs, etc. I like the idea of Luxor, writing the UI in XUL, but it's GPLed and I don't want to mess with that. I like Apache-style licenses better (like the MIT) "do what you want with the code, but don't sue me." That's a good license. The other projects like this don't seem ready for prime time yet (Xulux) so I'm going back to hand-coding my stuff. Speaking of IDEs, Eclipse is okay also, though you have to "import" your project which annoys me. I just ran across this free XML/JSP module which looks good and was my other complaint until now. But I'm digressing, I don't think Eclipse has a UI editor. -Russ [Russell Beattie Notebook] Firstly don't bother with the solareclipse plugin for eclipse, its pretty basic and has some awful bugs (like using tab characters for indentations, yuck). XMLBuddy is much, much nicer. its integrated with eclipse's outliner, has full control over pretty-printing and it can even do DTD based tag completion etc. BTW there's an eclipse plugin now for Maven which creates the .project file for eclipse so that there's no need to 'import' your project.   Going back to defining UIs in markup - I think using markup to define Swing UIs is a great idea! If you don't want GPL then it appears you could use thinlets which seem pretty simple and self contained (though you don't get the source code), or JellySwing which is more powerful but a bit more complex as knowledge of Jelly helps, though it comes with source code and uses the Apache licence. Hopefully one day soon xulux will be a viable alternative using XUL as the XML language... 11:53:57 AM    comment []

eclipse tip of the day. Ever wondered how to apply a CVS patch in eclipse? Probably not :). But if you have its a little criptic. Click on a directory in the navigator which matches the directory the patch was created from. Right click. Select Compare With (just below Team), then Patch... You now get an apply patch wizard that you can iterate through each change in the patch and apply any ones you wish. Its really neat - it just takes a mental leap to guess that applying a patch is under the Compare With menu. 11:38:31 AM    comment []

[drools] test coverage. drools test coverage information is now available. Only about 28% tested, overall. But at least I can now visualize the weak parts. Have you run clover on your codebase lately?... [bob mcwhirter] Neat stuff. As soon as I can get the clover plugin for Maven working, I'll have a play with Clover too :)... 11:14:38 AM    comment []

... Tried out Maven. Looks very good, if somewhat complex to get going initially. I like the idea that you can specify all your dependencies in one project file. What would be really good is if you could bootstrap an entire build process starting with just the project.xml file... [Pushing the envelope] Thats the idea.  If you have a project.xml then you just type 'maven' and it builds everything you need. You only need to mess around with a maven.xml if you've got something you want to customize. Mucked about with my toy project, ViewBeans a bit more. Knocked up a quick-n-dirty site using Maven, and got the code doing string replacements based on bean introspection (including nested beans), which is quite cool. Need to learn more about taglibs, and how it might be accessed from within a JSP, and possibly consider how to deal with subclasses. [Pushing the envelope] 2 open source projects that could be worth looking at... commons-beanutils from Jakarta contains heaps of useful utility methods for working with beans, introspection etc. There's also something support for DynaBean objects, which are like dynamic beans that can be defined at runtime. They make a neat wrapper around regular java beans too so you can access them in a Map-like manner. Jexl is cool, its a simple expression language for evaluating expressions on beans. Jexl is a little like the Velocity expression language and is a super set of the JSP Expression Language. So you can use it to navigate bean property trees, accessing maps, arrays, collections, indexed properties and 'map properties' (a term coined by the commons-beanutils project for getter methods that take a String argument) as well as methods. So the following are valid Jexl expressions... foo.bar foo.bar == 'abc' foo.bar.cheese[3].map['abc'].doSomething(abc, 123, 'xyz') 8:16:39 AM    comment []