jquery - 406 Not acceptable Error in jquery autocomplete

Question

I am trying to use jquery autocomplete with spring mvc I am using spring 3.2.3 jars along with jackson-mapper-asl-1.9.7 jackson-datatype-json-org-2.0.2 jackson-core-asl-1.9.7 jackson-core-2.0.2 for my application.

<script type="text/javascript">
    function split(val) {
        return val.split(/,\s*/);
    }
    function extractLast(term) {
        return split(term).pop();
    }

    $(document)
            .ready(
                    function() {

                        $("#userName")
                                .autocomplete(
                                        {
                                            minLength : 2,
                                            source : '${pageContext. request. contextPath}/get_country_list.htm'
                                        });

                        $("#technologies")
                                .autocomplete(
                                        {
                                            source : function(request,
                                                    response) {
                                                $
                                                        .getJSON(
                                                                "${pageContext. request. contextPath}/get_tech_list.htm",
                                                                {
                                                                    term : extractLast(request.term)
                                                                }, response);
                                            },
                                            search : function() {
                                                // custom minLength
                                                var term = extractLast(this.value);
                                                if (term.length < 1) {
                                                    return false;
                                                }
                                            },
                                            focus : function() {
                                                // prevent value inserted on focus
                                                return false;
                                            },
                                            select : function(event, ui) {
                                                var terms = split(this.value);
                                                // remove the current input
                                                terms.pop();
                                                // add the selected item
                                                terms.push(ui.item.value);
                                                // add placeholder to get the comma-and-space at the end
                                                terms.push("");
                                                this.value = terms
                                                        .join(", ");
                                                return false;
                                            }
                                        });

                    });
</script>

and my controller goes like this

@RequestMapping(value = "/get_country_list", method = RequestMethod.GET, headers = "Accept=*/*")
public @ResponseBody
List<String> getCountryList(@RequestParam("term") String query) {
    List<String> countryList = dummyDB.getCountryList(query);
    System.out.println("aotuController"+query);
    if(!countryList.isEmpty())
    {
        System.out.println(countryList.get(0));
    }
    return countryList;
}

@RequestMapping(value = "/get_tech_list", method = RequestMethod.GET, headers = "Accept=*/*")
public @ResponseBody
List<String> getTechList(@RequestParam("term") String query) {
    List<String> countryList = dummyDB.getTechList(query);

    return countryList;
}

its showing error 406 not acceptable while running.