java - Spring boot - 两个不同请求之间的 HttpSession 为 null

Question

首先，当我调用 API“/fetch/event/1221”时，我可以设置 session 属性，但是当我调用“fetch/partcipant”API 时，我得到的 httpSession 为 null。我该如何解决这个问题？

@RequestMapping(value = "/fetch/event/{eventId}", method = RequestMethod.GET)
        public SuccessResponse<Event> fetchEvent(@PathVariable("eventId") String eventId, HttpServletRequest httpServletRequest) throws ExecutionException, InterruptedException {
            Event event = eventService.getEventById(eventId);
            HttpSession httpSession = httpServletRequest.getSession(false);
            httpSession.setAttribute("event", event);
            return new SuccessResponse<Event>(event);
        }


 @RequestMapping(value = "/fetch/participant", method = RequestMethod.GET)
    public SuccessResponse<List<Participant>> getListOfActiveParticipants(HttpServletRequest httpServletRequest) throws ExecutionException, InterruptedException {
        HttpSession httpSession = httpServletRequest.getSession(false);
        Event event = (Event) httpSession.getAttribute("event");
        System.out.println((Event) httpSession.getAttribute("event"));
        return new SuccessResponse<>(participantService.getParticipants("ALL", event.getId()));
    }

Answer 1

首先，您在 /fetch/event/ 中使用 httpServletRequest.getSession(false) ，如果没有当前 session ，则不会创建 session 。如果当前没有 session ，请将其更改为 true 以强制创建一个新 session :

 HttpSession httpSession = httpServletRequest.getSession(true);

session 创建后，会通过响应头中的cookie返回 session id:

< HTTP/1.1 200
< Set-Cookie: JSESSIONID=6AD698B82966D43FF395E54F5BFCEF65; Path=/; HttpOnly

为了告诉服务器使用特定的session，后续的请求应该通过cookie包含这个session id。如果是curl ，你可以这样做:

$ curl -v --cookie "JSESSIONID=6AD698B82966D43FF395E54F5BFCEF65" http://127.0.0.1:8080/fetch/partcipant

这将添加以下 HTTP 请求 header :

> GET /fetch/participant HTTP/1.1
> Host: 127.0.0.1:8080
> Cookie: JSESSIONID=6AD698B82966D43FF395E54F5BFCEF65

然后在 getListOfActiveParticipants() 中，您应该获取在 fetchEvent() 中创建的 session