I have a Mapnik server running under Tomcat, built using the spatialinteractive mapnik-jni bindings for Mapnik, connecting to my custom datasource using a plugin we developed. It's been running for a while now with no issues.
There is a new requirement to use a variable coming from the web client that will be sent to the datasource as part of the query. Obviously I have it in my server code, so I was looking for a way to use the Mapnik-jni MapDefinition class to keep this data, pass it to the C++ engine and from there to the datasource as part of the query, after resolving the variable in the styling xml. I thought it was a viable plan but it doesn't look like this is supported.
