Spring MVC 学习之 400 错误

如果一个方法中有参数被 @Valid 标注了，但该参数后面没有紧跟一个 BindingResult 类型的参数，那么提交到该方法时，将返回 400 错误。

错误消息将会是：The request sent by the client was syntactically incorrect ().

错误的方法定义 1 ：（错误原因：没有 BindingResult 参数）

@RequestMapping({"error400" }) 

public String error400(@Valid @ModelAttribute("testForm") TestForm testForm) { 

    return"test"; 

}

错误的方法定义 2 ：（错误原因：没有紧跟在 @Valid 参数之后）

@RequestMapping({"error400" })

public String error400(@Valid @ModelAttribute("testForm") TestForm testForm, Model model, Errors result) {

    return"demo/front/test";

}

也可参考 DefaultHandlerExceptionResolver.java 中的方法说明：

/** 

 * Handle the case where an {@linkplain ModelAttribute @ModelAttribute} method 

 * argument has binding or validation errors and is not followed by another 

 * method argument of type {@link BindingResult}. 

 * By default an HTTP 400 error is sent back to the client. 

 * @param request current HTTP request 

 * @param response current HTTP response 

 * @param handler the executed handler 

 * @return an empty ModelAndView indicating the exception was handled 

 * @throws IOException potentially thrown from response.sendError() 

 */

protectedModelAndView handleBindException(BindException ex, HttpServletRequest request, 

        HttpServletResponse response, Object handler)throws IOException { 

    response.sendError(HttpServletResponse.SC_BAD_REQUEST); 

    returnnew ModelAndView(); 

}