I know that this question is old but in case anybody has this problem there is new better solution since JAX-RS 2.0. Solution is @BeanParam. Due to documentation:
The annotation that may be used to inject custom JAX-RS "parameter aggregator" value object into a resource class field, property or resource method parameter. The JAX-RS runtime will instantiate the object and inject all it's fields and properties annotated with either one of the @XxxParam annotation (@PathParam, @FormParam ...) or the @Context annotation. For the POJO classes same instantiation and injection rules apply as in case of instantiation and injection of request-scoped root resource classes.
If you are looking for extended explanation on how this works please look at article I've found: http://java.dzone.com/articles/new-jax-rs-20-%E2%80%93-beanparam