With the information you provided, it seems that you configurations it's ok.
To have a point of comparison, you can take a look at the example we have:
https://github.com/apache/tomee/tree/master/examples/jaxrs-json-provider-jettison
and also to this article:
https://www.tomitribe.com/blog/upgradi
We upgraded from 1.7.4 to 7.1.0, and we're in the process of testing. We came
across a problem (see error below) related to the new johnzon implementation.
To work around the problem, we're attempting to revert back to the previous
implementation by adding resources.xml and openejb-jar.xml. W
