jquery - input type ajax post request shows error 415 (Unsupported Media Type) -

i want post file using ajax request, error 415 (unsupported media type)

code

$('#productsubmit').click(function(e) {   var data = new formdata($('input[name^="image"]'));        jquery.each($('input[name^="image"]')[0].files, function(i, file) {     data.append(i, file);   });   console.log(data);   $.ajax({     type: "post",     url: "http://test-app.appspot.com/items/data.id/images",     //enctype: 'multipart/form-data',     mimetype: 'multipart/form-data',     contenttype: false,     processdata: false,     data: data,     success: function (data) {       alert("data uploaded: ");       $('#product_data').submit();     },     error: function(jqxhr, textstatus, errorthrown) {       alert(11);       console.log( errorthrown );     }   });    });