The Java™ Architecture for XML Binding (JAXB) provides an API and tools that automate the mapping between XML documents and Java objects.

JMESPath is a query language for JSON

WireMock is an HTTP mock server. At its core it is web server that can be primed to serve canned responses to particular requests (stubbing) and that captures incoming requests so that they can be checked later (verification). It also has an assortment of other useful features including record/playback of interactions with other APIs, injection ...