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问题描述
在同一请求中，一方面我得到了NullPointerException，另一方面在代码中也没关系.
In the same request at one part, I am getting NullPointerException and at other part of code it is ok.
@Controller
@RequestMapping(value="/event")
public class EventController {
@Autowired
EventValidator eventValidator;
@Autowired
private EventService eventService;
@InitBinder
private void initBinder(WebDataBinder binder) {
System.out.println(eventValidator.toString()); <<—— NULL HERE
binder.setValidator(eventValidator);
}
@RequestMapping(value="/add_event",method = RequestMethod.POST,produces=MediaType.APPLICATION_JSON_VALUE)
@ResponseBody
public ResponseEntity<AjaxJSONResponse> postAddEventForm(@RequestPart("event") Event event, MultipartHttpServletRequest request,BindingResult result) throws MethodArgumentNotValidException, NoSuchMethodException
{
eventValidator.validate(event, result); <<——- OK HERE
//Check validation errors
if (result.hasErrors()) {
throw new MethodArgumentNotValidException(
new MethodParameter(this.getClass().getDeclaredMethod("postAddEventForm", Event.class, MultipartHttpServletRequest.class, BindingResult.class), 0),
result);
}
Boolean inserted = eventService.addEvent(event);
String contextPath = request.getContextPath();
String redirectURL = StringUtils.isEmpty(contextPath)?"/event":contextPath+"/event";
return new ResponseEntity<AjaxJSONResponse>(new AjaxJSONResponse(inserted,"Event Added Successfully",redirectURL), HttpStatus.OK);
}
}
在同一请求中，initBinder()函数中的eventValidator为NULL，而在postAddEventForm()函数中的eventValidator中包含该实例.
In same request, in initBinder() function eventValidator is NULL and in postAddEventForm() function eventValidator is holding the instance.
请对此提供帮助.
推荐答案
initBinder()方法的访问说明应为public-
Access specifier of initBinder() method should be public -
public void initBinder(WebDataBinder binder) {
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