Spring MVC @SessionAttribute Missing session 类型 String[] 属性错误

Question

I was having some problem when trying to use @SessionAttribute in Spring MVC Controller. Basically what I am trying to do is, in my API, I want to retrieve from the session, if it contains data, fetch it out, then remove the session itself. Here is my controller class:

@SessionAttributes({WebKeys.SEARCH_RESULT_LIST_THREE})
public class ALController {
    @RequestMapping(value = "/search.do", method = { RequestMethod.POST })
    public String doSearchList(Model model, @ModelAttribute("attendanceTO") AttendanceTO attendanceSearchForm, @SessionAttribute(WebKeys.SEARCH_RESULT_LIST_THREE) String[] selectedRecords) {
        // removed code

        attendanceSearchForm.setSelectedRecords(null);
        // checking from session
        if(selectedRecords != null && selectedRecords.length > 0){
            attendanceSearchForm.setSelectedRecords(selectedRecords);
        }
        model.addAttribute("selectedRecords", selectedRecords);
        // remove session
        model.addAttribute(WebKeys.SEARCH_RESULT_LIST_THREE, null);
    }
}

At this point of time, the session is not existed yet. I only set up the session when user submit form. I am getting this error messages:

Missing session attribute 'key.searchResultList.three' of type String[]

Any ideas on how to resolve this? Thanks!

Answer 1

U should add a required parameter to the @SessionAttribute annotation and set its value to false,meaning it's not necessary,like

@SessionAttribute(name=WebKeys.SEARCH_RESULT_LIST_THREE,required=false)