FormParamInjector List<T>

Environment: Jboss AS 7.1 + Restaeasy 3.0.9Final + JAX RS 2 + EJB 3

Situation: @PUT resource with param like "@FormParam( "departmentId" ) List<Long> departmentIds"

JEE API @FormParam Description says: " ... The type T of the annotated parameter must either:

Be a primitive type
Have a constructor that accepts a single String argument
Have a static method named valueOf or fromString that accepts a single String argument (see, for example, Integer.valueOf(String))
Be List<T>, Set<T> or SortedSet<T>, where T satisfies 2 or 3 above. The resulting collection is read-only.
..." -->
https://docs.oracle.com/javaee/6/api/javax/ws/rs/FormParam.html

Problem: FormParamInjector injects List<String> as param when it must be injected as List<Long> because Long has a constructor that accepts a single String argument.