Introduction
The purpose of this tutorial is not at all to teach you on SOA but to draw your attention on points that the developer(s)/deployer(s) will be confronted during the design/development and release management phases.
Designing a Service Oriented Architecture seems very obvious for most of us but implies that different parameters are taken into account :
- Identification of the layers of the application,
- Definition of the services,
- Granularity (what are the boundaries of a service, ...),
- Dependency with libraries,
- Testing and debugging strategies,
- Deployment procedure,
- Infrastructure
Some of the points mentioned are particular to SOA world like granularity and definition of service boundaries but others are mostly found in all IT projects. This is really important to keep them in your head because they will impact the project life cycle, quality of the deliverable, efficiency of the team and project duration/cost.
In this second part of the tutorial we will investigate some of the points mentioned and applied them to a real application. The application will be designed around different components (= bundles in the OSGI jargon) and deployed into ServiceMix Kernel. ServiceMix Kernel or SMXKNL is an OSGI platform created top of Apache Felix OSGI server, integrating Spring Dynamic Modules to facilitate the build of Spring application and PAX components who provide tools managing deployment of component and web support.
For more information about the projects mentioned, I recommend that you have a look on their respective web site.
Here is a picture of the report incident application that this tutorial will cover :
To summary, the application is listening for incidents coming from web service or files. According to the origin, the content (= incidents) are transformed into their corresponding objects using for the CSV file, a new camel component : camel-bindy and for the Web Service camel-cxf component. Each message transformed is placed in a queue handled by ActiveMQ engine. All the messages (containing the objects) are next processed by a Bean service who will (with the help of injection of dependency provided by Spring) save the incidents in a DB.
A small Apache Wicket web application running in Jetty Web server provide to the users an screen to consult the incidents created.
Prerequisites
This tutorial uses:
- Maven 2.0.9 to setup the Camel project and for dependencies for artifacts,
- Eclipse Ganymede 3.4.x,
- Service Mix Kernel 1.1.0,
Note: The sample project can be downloaded, see the resources section.
Step 1 : Initial Project Setup
Next, you import these projects into your favorite workspace of Eclipse.