G2One is the software company delivering open source projects Grails and Groovy. This company is made of 6 java experts. YOçu can find all the details in this article.
SpringSource expect to integrate Grails in dm server, the OSGi paltform.
Ruby on Rails has now a serioous competitor.
I bet on this as the major infrastructure component for software within near future.
Separation of Concern (SoC) is really important to me and goes beyond simple separation of layers os a software implementation. I should add “cohesive”, but this is part of the same idea: everythings doing the right thing in the rigth area.
This principle does apply obviously to the source code as a programming practice, useing a tool as maven that introduce some structure into the code organization. But it also apply to the architecture (SCA), the deliverables (DLL…and its hell), platform (OSGi / Spring DM server), components/framework (IoC, MEF), and methodologies (Agile).
The last one could be amazing, but I think the rational is the same: change adpoption. Kevlin Henney in his post Manage component dependencies for improved system quality says:
Another consideration in managing dependencies is the question of change. The dependency structure of a system can enable or discourage change, which makes dependency management a question of architecture, not merely one of fine-grained code quality
Having a system allowing effective depedency management at compile-time will ease test infrastructure setup (abaility to test a piece of code without having the entire system setup), hence quality…humm…be sure to automate your test to really ensure quality (doing manual repetive stuff is the best way to do it in a bad way over the time).
Having a system allowing effective depedency management at run-time will ease deployement as you will be able to do hotswapping of components even when they are running as for OSGi platforms.
Having a system allowing effective depedency management at run-time with version management, will allow multi-tenant applications and smooth upgrade…and probably start to solve the DLL’s hell.
I’m currently having a look at spring platform. I’m trying to convert a web application into OSGi module. I get the following error:
Bundle: com.springsource.org.apache.xerces_2.8.1 - Import-Package: org.apache.xml.resolver.readers; version=”[1.2.0,1.3.0)”
This means that the bundle xerces requires another bundle having package org.apache.xml.resolver which is not in your repository. So, you simply ahev to download the bundle from SpringSource Entreprise Bundle Repository, then restart the platform.
Sometimes the message is not so clear (I get with trying to use axis bundle). A way to better diagnose the problem is to use Equinox’s telnet concole.
This console can be accessed via telnet on port 4201. You can download PuTTY telnet client. After connection, youo should have this prompt:
osgi>
Use the command “ss” to list all the install bundles and check for the bundles having status “installed”.
You will notice the id of the bundle starting each line. Execute the command “start <id>” to start a bundle, then you should see a clear stack helping you to diagnose the problem.