如何检查json对象是否为null?

时间:2015-09-15 09:39:06

标签: javascript jquery json spring-security

我尝试使用jquery验证插件验证表单。我正在尝试在表格中是否有emailId,如果不允许注册则不是。 但是,它显示json对象总是大于零。我尝试使用getjson,它在localhost中不起作用。那么,我哪里错了?

的login.jsp

$('input#emailId').blur( function() {
                    $.ajax({
                        url:'/getUserByEmailOrPhone-'+$('#emailId').val()+'-'+$('#contactNumber').val(),
                        type:'GET',
                        data: 'json',
                        success:function(json){
                            if (json.length == 0)
                                {
                                    $('.email-check').append('<span class="glyphicon glyphicon-ok form-control-feedback" aria-hidden="true" id="tt2" clientidmode="Static" runat="server" Visible="False"></span>');
                                  }
                            else{
                                  alert('user exists');
                                  $('.email-check').append('<span class="glyphicon glyphicon-remove form-control-feedback" aria-hidden="true" id="tt2" clientidmode="Static" runat="server" Visible="False"></span>');
                            }
                        }
                });
            });

AppController.java

@RequestMapping(value={"/getUserByEmailOrPhone-{emailId}-{contactNumber}"}, method = RequestMethod.GET)
public @ResponseBody User getUserByEmailOrPhone(@PathVariable("contactNumber") String contactNumber,
        @PathVariable("emailId") String emailId,ModelMap model){
        return service.getUserByEmailOrPhone(emailId, contactNumber);
}

1 个答案:

答案 0 :(得分:0)

如果json变量包含正确的值,那么您可以执行as-

成功:函数(JSON)
    {
    if(json === undefined)     {
    //你的行动     } ...