In our last project, we faced 2 challenges of how to build the SaaS platform including various modules; some are developed by ourselves and some are third parties (Forum, Wiki, Mail, etc.). With third-parties, we limit modifying their code base and database schema due to client's requirements. Here are our challenges:

Challenge 1: When a new user is registered, some our modules need to acknowledge and have re-actions. For example:

• Document Management module creates a personal document workspace for that user.
• Calendar module creates a personal calendar for that user.
• Forum and Wiki register that user to their user database because Engroup supports Single Sign On (SSO) mechanism. That means any user registered to Engroup user database can access Forum and Wiki resources without registering their user database.

• Simple - if you already know Spring and Enterprise Integration Patterns, you can quickly use this library.
• Extensible - Spring Integration does not support many adapters like ServiceMix or Mule does; but it is easy to add new adapters by extending. In the next post, I will write an example of how to extend Spring Integration.
• Compatible - Our platform is built on Osgi, like Spring Integration and ServiceMix 4. However, ServiceMix 4 is not mature enough as well as it lacks of documentation.
• Friendly license - ServiceMix has friendly license, too. However, we are afraid that CPAL of Mule may prevent us from developing our commercial project.
• Lightweight - We can use Spring Integration as a part of our application while ServiceMix and Mule need to be deployed on separate servers.

If you have a need of using a Java ESB, Spring Integration may be a good candidate. I will write some posts about Spring Integration examples and how to extend Spring Integration as we managed in our projects in the near future. Keep reading!