java - Can't submit JSON object to JSP -

i'm trying send json object jsp parse. javascript code is:

function senddata(field1, oper1, value1, field2, oper2, value2, field3, oper3, value3){         var formdata = {"field1":field1, "oper1":oper1, "value1":value1, "field2":field2, "oper2":oper2, "value2":value2, "field3":field3, "oper3":oper3, "value3":value3};         $.post("<%=request.getrequesturl().tostring()%>getinfo.jsp", {formdata:formdata}, function(response){alerthere(response)});     }  function alerthere(){         window.alert("post successful!")     } 

my submit button is:

<input type="submit" value="search" name="submit" class="srchbutton" onclick="senddata(document.getelementbyid('field1').value, document.getelementbyid('oper1').value> 

there several more fields passed in javascript button on click, didn't want post long of line.

when try post text data in form, web developer console flashes path jsp disappears. it's fast see error. if there's no data, post successful, alerthere function in $.post() called correctly. i'm not sure if i'm missing something.

assuming have servlet on server side handles data sending jsp page create pseudo-class using javascript, parses json , sends server. example:

javascript , jquery

function someclass (){   this.field1 = $("#field1").val();   this.oper1 = $("#oper1").val();   this.value1 = $("#value1").val();   // etc. every field want send } 

note: i'm assuming every field have id.

function alerthere(){    window.alert("post successful!") } 

jquery , ajax

$("#someid").click(function(){     event.preventdefault(); <-------- if replace submit button simple button,                                       don't need this.     var formdata = new  someclass();      $.ajax({       url:"servletname",        data: json.stringify(formdata),        datatype:"json",     }).done(function(response){          alerthere(response);     });  }); 

html

<input type="submit" value="search" id="someid" name="submit" class="srchbutton">