Document that AtlasMap user classes may need to be registered for ref…

[zbendhiba]

…lection fixes #2319

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[jamesnetherton]

Just a suggestion, we don't have to do this. But to get confidence that everything is working properly in native mode, maybe we should not return Person from the JAX-RS methods.

E.g this:

camel-quarkus/integration-tests/atlasmap/src/main/java/org/apache/camel/quarkus/component/atlasmap/it/AtlasmapResource.java

Line 96 in 312f503

return producerTemplate.requestBody("atlasmap:mapping/json/atlasmapping-xml-to-java.json", xml, Person.class);

And this:

camel-quarkus/integration-tests/atlasmap/src/main/java/org/apache/camel/quarkus/component/atlasmap/it/AtlasmapResource.java

Line 126 in 312f503

return producerTemplate.requestBody("atlasmap:mapping/json/atlasmapping-csv-to-java.json", csv, Person.class);

Otherwise Quarkus RestEasy is effectively still doing the reflective class registration.

[zbendhiba]

@jamesnetherton
I changed the sentence in the doc to : "you may need to register".
I've add another class to test the need to register for reflection + examples. If we delete the @RegisterForReflection, the tests fail in native mode.