I saw on twitter the reference of an article (in french):
http://javaetmoi.com/2016/08/migrer-vers-spring-boot/

That article concludes with something along the lines of  "Besides the
EhCache and Maven configuration, Petclinic does not hold a single line
of XML anymore".

Looking at the code, we can remove more XML if you want. This PR migrates
the cache infrastructure to EhCache 3 and JCache (JSR-107). This also
reduces the number of dependencies.

This reverts commit be048ae2.

- remove custom xml view, use springboot builtin xml view
- remove oxm maven dependency
- remove json-simple maven dependency (seems not relevant anymore)
- update vetsXml test using xpath

- In the Jdbc implementation: pets belonging to a visit were not added.
- In the Jpa implementation: query variable was wrong.
- Test case: AbstractClinicServiceTests.shouldFindVisitsByPetId()

CallMonitoringAspect is not invoked when spring-data-jpa is used.  Spent
4 hours trying to understand why jmx bean wasn't showing message counts.
Use JPA or JDBC if you want call counts exposed via JMX / AOP