Ajax post dataform to weblogic connection refused

Hi all.

I want to post dataform to weblogic uing ajax.

this is my code.

 var formdata = new FormData();

  for (var i=0; i < a.length; i++) {
          if(a[i].name =='newfile'){
          formdata.append(a[i].name,$('#newfile').files);
            alert(a[i].name+":"+ a[i].value)
    }
        } 
  $.ajax({
      type: "POST",
      url: 'http://localhost:8080/ckedit/test',
      data: formdata,
      //use contentType, processData for sure.
      contentType: false,
      processData: false,
      beforeSend: function() {
          alert('beforeSend');
      },
      success: function(msg) {
       alert(msg);
      },
      error: function() {
       alert('error');
      }
  });

when it run ,ithas error : err_connection_refused.

Only post dataform it raise error.

Thanks.