Configuring a deployed BOF module

Sometimes you might want a BOF module to be configured externally post deployment. You might want to use an XML file or a properties file for this purpose.

The naive way would be to checkout the implementation jar, unzip it, edit the config file, rezip it, and check in the updated jar. That’s too horrible to contemplate, for too many reasons to list.

There is another way. BOF anticipated the need for external, non-jar files to be accessible in the module classpath. Such external files are called downloadable attachments. Attachments in general are any non-jar files that the module author wants to be deployed with the module – say a javadoc zip, or license files. Typically you want these in the docbase, but you don’t want them in the module classpath. If you flag an attachment as downloadable though, it goes all the way to the class loader.

So, if you want a config file to be externally accessible and yet visible in the classpath you make it a downloadable attachment. In Composer you would go to your module’s “Deployment” tab, add the file as an attachment and check the downloadable option.

Downloadable Attachment in Composer

Then, at any time post deployment, you just need to check out, edit, and check back in the config file. The updated version will be hot deployed to the BOF module. You have to control the security of the attachment, but the rest of your module preserves its integrity.

Remember that hot deployment is only revealed to subsequent module instantiations, so don’t hold a cached reference to your module or you won’t see any updates. Prefer newModule or newService on demand – they’re quick.