Chapter 6. @HeaderParam

The @HeaderParam annotation allows you to map a request HTTP header onto your method invocation. 
  GET /books?num=5

   
   @GET
   public String getBooks(@HeaderParam("From") String from) {
   ...
   }
As with @PathParam, the type of parameter can be a primitive, a String, or a class with a String constructor or static valueOf() method. For example, MediaType has a valueOf() method, so you could do the following: 

   @PUT
   public void put(@HeaderParam("Content-Type") MediaType contentType, ...)