title: Jersey - validate REST service parameters
body: <p>is there any tool to simply validate query params using Jersey (and Maven)? I'm trying to do something like this using @NotNull annotation (jersey-bean-validation):</p>
  
  <pre><code>@GET
  @Path("/count")
  @Produces(MediaType.APPLICATION_XML)
  public Response count(@NotNull @QueryParam("my_param") String my_param) {
      //TODO automatically return 400 Bad Request if my_param is null
      return Response.ok("This is a response", MediaType.APPLICATION_XML).build();
  }
  </code></pre>
  
  <p>I'd like the method to automatically validate query parameters and return 400 Bad Request if no "my_param" is provided.</p>