caelum/vraptor — pull request #455 by joaopaulog (2012-08-27 20:13:51+00:00)
Title: Fix @HeaderParam interceptor

The annotation `@HeaderParam` ([Issue 405](https://github.com/caelum/vraptor/issues/405)) is not working.

For example:
````java
@Post("/path")
public void method(@HeaderParam("Accept") String accept) {
// ....
}
````
The parameter *accept* doesn't receive your respective value, remaining with *null*.

This occurs due to two problems in `ParametersInstantiatorInterceptor`:
- The values to `@HeaderParam` are set in *attributes* of `HttpServletRequest`. But the default `ParametersProvider` (`IogiParametersProvider` ) search for values in *parameters* of `HttpServletRequest`.
- The values are set using `@HeaderParam` value as key. However, the key should be the name of parameter of method, for be able to relate the parameter with your value.