Server-side asynchronous support must be enabled

This rule flags the usage of the @Suspended annotations on parameter type AsyncResponse in a JAX-RS resource method if an applications web.xml contains <servlet-class> or configuration options other than <servlet-name>. If AsyncResponse is annotated with @Suspended the method is asynchronous and requires <async-supported>true</async-supported> to be set in the web.xml if it has configuration other than <servlet-name>. If the web.xml does not exist then asynchronous-supported is set true by default.

See Asynchronous REST with JAX-RS and MicroProfile for more information on asynchronous REST in JAX-RS.

See Server-side asynchronous support for more information on the behavior change to asynchronous support.