AngularJS: ignoring Content-Type parameter

I am currently struggling with an error that appears in my Chrome developer tools console

GET http://localhost:8080/movie_db/search/movie?movieTitle=Machete 415 (Unsupported Media Type)

when I try to connect to my REST service with angular JS. Since I had this issue before when I tried to access the REST service via a Simple REST plugin in Chrome, I assume that most likely a missing Content-Type header parameter is the reason for that (should be Content-Type: 'application/json').

Angular JS website says, that one could set header parameters as follows: $httpProvider.defaults.headers.get['My-Header']='value'. Regretfully this didn't have any impact and the problem still exists.

Thus I'd like to know how I can manipulate the header parameters with angular JS that are sent over to my REST service.

Right at the moment, my code looks like this: 

  function SearchMovieController($scope, $resource) {

  $scope.SearchMovie = $resource('http://localhost\\:8080/movie_db/search/:action',
            {action: 'movie', movieTitle: 'Machete'},
            {get: {method: 'JSONP', headers: [{'Content-Type': 'application/json'}, {'Accept' : 'application/json'}]}});

        $scope.SearchMovie.get()
    }

Server side looks as follows (I use Spring MVC):

CONTROLLER:

@Controller
@RequestMapping( "/search/movie" )
public class SearchController { // TODO rename?

private final TheMovieDBService theMovieDBService;

@Autowired
public SearchController( TheMovieDBService theMovieDBService ) {
    this.theMovieDBService = theMovieDBService;
}


@ResponseBody
@RequestMapping( method = RequestMethod.GET, produces = "application/json", consumes = "application/json" )
public Map<String, Object> search( @RequestParam String movieTitle ) {
    Map<String, Object> response = new HashMap<String, Object>();

    try {
        TheMovieDBSearchResult searchResult =  theMovieDBService.searchMovie( movieTitle );
        response.put( "result", searchResult );
        response.put( "success", "true" );
    } catch ( EncoderException e ) {
        response.put( "success", "false" );
    }
    return response;
}
}

web.xml

 <servlet>
    <servlet-name>json</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

    <init-param>
        <param-name>contextClass</param-name>
        <param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>
    </init-param>

    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>com.u6f6o.apps.movie_db.config.web.ServletConfig</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>json</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>

I had to step through all of Angular's $httpBackend stuff just recently, and JSONP uses a different method to load data than the other requests.

EDIT: The code in question

So if you specify jsonp has your method it is using the following method to load your data. This will, of course, completely ignore any headers you set yourself.

in $httpBackend:

function jsonpReq(url, done) {
    // we can't use jQuery/jqLite here because jQuery does crazy shit with script elements, e.g.:
    // - fetches local scripts via XHR and evals them
    // - adds and immediately removes script elements from the document
    var script = rawDocument.createElement('script'),
        doneWrapper = function() {
          rawDocument.body.removeChild(script);
          if (done) done();
        };

    script.type = 'text/javascript';
    script.src = url;

    if (msie) {
      script.onreadystatechange = function() {
        if (/loaded|complete/.test(script.readyState)) doneWrapper();
      };
    } else {
      script.onload = script.onerror = doneWrapper;
    }

    rawDocument.body.appendChild(script);
  }