javascript - 400 error - The request sent by the client was syntactically incorrect -

i'm trying send ajax request spring controller, request doesn't reach controller. instead 400 error following description: request sent client syntactically incorrect. javascript function sends request looks this:

 function rzdeleteevent() { saveuncheckedeventgroups(); $.ajax({   url: '${param.removeeventurl}&starttime=' + activestarttime + "&endtime=" + activeendtime,   type: 'post',   datatype: 'json',   data: json.stringify(activeevent),   contenttype: 'application/json',   success: function(result) {     hideuncheckedeventgroups(result);     ical.hidepreview();     ical.render(result);     sortgroupfilters();   },   error: function(jqxhr, textstatus, errorthrown) {     ajaxerrormsg();   } }); } 

the controller is:

@controller @requestmapping("/resourcereservationcalendar/") @sessionattributes(selected_resources_list) public class resourcereservationcalendarcontroller extends calendarbasecontroller {  private static final string calendar_view = "resourcereservationcalendar";  private static final string select_view = "resourceselect";  private static final int zero_hour = 0;  private static final int twenty_four_hour = 24;  @autowired private resourcerepository resourcerepository;  @autowired private userrepository userrepository;  @autowired private userresourceservice userresourceservice;  @autowired private controlvaluerepository controlvaluerepository;  @modelattribute(value = "reservationtypes") public list<code> getreservationtypes() {     return cacheservice.getvalidcodesofcodegroup(resource_reservation_type); }  @requestmapping(method = get) public string getview(modelmap modelmap) {     controlvalue calendargridstarttimecontrolvalue = controlvaluerepository.findbycode(calendar_grid_start_time);     controlvalue calendargridendtimecontrolvalue = controlvaluerepository.findbycode(calendar_grid_end_time);     int calendargridstarttime = calendargridstarttimecontrolvalue.getlongasintvalue();     int calendargridendtime = calendargridendtimecontrolvalue.getlongasintvalue();     if (calendargridstarttime < zero_hour || calendargridstarttime > twenty_four_hour) {         calendargridstarttime = allday_start_hour;     }     if (calendargridendtime < zero_hour || calendargridendtime > twenty_four_hour         || calendargridendtime <= calendargridstarttime) {         calendargridendtime = allnight_start_hour;     }     modelmap.addattribute("calendargridstarttime", calendargridstarttime);     modelmap.addattribute("calendargridendtime", calendargridendtime);     modelmap.addattribute(getresourceselectiondto());     modelmap.addattribute(new serialreservationcommand());     addputmethodto(modelmap);     return calendar_view; }  @suppresswarnings("unchecked") private resourceselectiondto getresourceselectiondto() {     return new resourceselectiondto(userrepository.findbyid(getuserid()).getresources()); }  @requestmapping(method = get, params = "content=json") @responsebody public list<calendargroupjson> getreservations(@modelattribute interval interval) {     return getgroups(interval); }  @suppresswarnings("unchecked") private list<calendargroupjson> getgroups(interval interval) {     list<calendargroupjson> calendargroupjsons = new arraylist<calendargroupjson>();     list<resource> resources = resourcerepository.findresourcedtos(getuserid(), interval);     (resource resource : resources) {         calendargroupjsons.add(jsonconverterservice.converttojsongroup(resource, interval));     }     return calendargroupjsons; }  @requestmapping(method = get, value = "select") public string getselectview(modelmap modelmap) {     modelmap.addattribute(getresourceselectiondto());     addputmethodto(modelmap);     return select_view; }  @requestmapping(method = put) public string updateresourceselections(@valid resourceselectiondto resourceselectiondto, modelmap modelmap) {     userresourceservice.updateresourcesforuser(resourceselectiondto);     addputmethodto(modelmap);     return select_view; }  @requestmapping(method = post, params = "content=json") @responsebody public list<calendargroupjson> addnewresourcereservation(@requestbody updatecalendareventjson eventjson,                                                          @modelattribute interval interval,                                                          @modelattribute education defaulteducation) {     system.err.println("addnewresourcereservation");     eventvalidator.validate(eventjson);     resourcereservationservice.createreservations(eventjson, defaulteducation);     return getgroups(interval); }  @requestmapping(method = post, params = "content=json", value = "update") @responsebody public list<calendargroupjson> updateresourcereservation(@modelattribute interval interval, modelmap modelmap,                                                          @requestbody updatecalendareventjson eventjson,                                                          @modelattribute education defaulteducation) {     system.err.println("updateresourcereservation");     eventvalidator.validate(eventjson);     resourcereservationservice.updateresourcereservation(eventjson, defaulteducation);     return getgroups(interval); }  @requestmapping(method = post, params = "content=json", value = "remove") @responsebody public list<calendargroupjson> removeresourcereservation(@requestbody updatecalendareventjson eventjson,                                                          @modelattribute interval interval) {     system.err.println("remove");     eventjson.setid("13515597");     resourcereservationservice.removeresourcereservationwithoutlearningevent(eventjson);     return getgroups(interval); } } 

only remove , update resource reservation post requests have problem. other post request (add new resource reservation) works correctly. looked similar problem, on so, none of proposed solutions helped in case.