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The cxf-rt-rs-json-basic dependency must be on the classpath as well.
Note, OpenAPI JSON (see also OpenApiFeature) allows referring to its new "components/requestBodies" section from the multiple "requestBody" elements (which can be found under the specific path/http verb sub-sections). By default the filter will instead inline the the "requestBody" definitions inside of "requestBody" elements, but one can experiment with referring to the "components/requestBodies" by configuring the filter to create the request bodies.
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