easyUI-form表单提交，正确返回但是不执行success

form表单

        submit0 :function(){                  $("#flowSubmmit").form('submit',{                          type : 'POST',                          dataType : "json",                         url : '/flow/submitTask.do',                          success : function(result) {                            var s=result;                            var result = eval('(' + result + ')');                              if (result.message==("ok")) {                                  $.messager.alert('提示!', '成功','info',                                          function() {                                              $('#supplementaryBudget').dialog('close');                                          });                              } else {                                  $.messager.confirm('提示',"失败!");                                  $('#supplementaryBudget').dialog('close');                              }                          }                      });            },

请求头

Host     localhost:8080User-Agent   Mozilla/5.0 (Windows NT 6.1; W…) Gecko/20100101 Firefox/55.0Accept   text/html,application/xhtml+xm…plication/xml;q=0.9,*/*;q=0.8Accept-Language  zh-CN,zh;q=0.8,en-US;q=0.5,en;q=0.3Accept-Encoding  gzip, deflateContent-Type     application/x-www-form-urlencodedContent-Length   275Referer  http://localhost:8080/basic/toTaskManager.doCookie   JSESSIONID=BB393F5999EC3BF6A85CBE64B96264BBConnection   keep-aliveUpgrade-Insecure-Requests    1

响应头

Server  Apache-Coyote/1.1Content-Type    text/plain;charset=UTF-8Content-Length  16Date    Thu, 28 Sep 2017 08:49:47 GMT

问题：
form表单提交，响应类型text/plain，不走sucess，直接结束
但是页面显示内容如下

即使后面我返回text/html，json也没有用。