RESTEASY-2227 specifically called for observing the presence of @PostConstruct annotated methods in the context of CDI being enabled. However, the javadoc for @PostConstruct says, "This annotation must be supported on all classes that support dependency injection." Since JAX-RS implementations supprt injection by @Context regardless of the presence of CDI, it seems that field/property/class validation should occur after the execution of a @PostConstruct annotated method regardless of the presence of CDI.

Moreover, in the case of an EJB @PostConstruct lifecycle interceptor bound to an EJB serving as a JAX-RS resource or provider, validation should occur after the execution of the interceptor.