springMVC表单post提交较长字符串显示400错误？

Question

POST提交较短字符串时没问题，稍长字符串就显示400错误，修改tomcat的server.xml没用

表单只有如下两个字段，这个content长度就会报错

控制器代码

//处理新闻评论表单提交
@RequestMapping(value = "/news", method = RequestMethod.POST)
public String doReplyNews(@Validated NewsReplyFormBean newsReplyFormBean, @RequestParam("newsId") int newsId, BindingResult bindingResult, Model model, HttpSession httpSession)
{
    //表单校验出错
    if(bindingResult.hasErrors())
    {
        this.fillNewsPageContent(model, newsId);
        return "news";
    }
    //表单校验成功
    else
    {
        User user = (User)httpSession.getAttribute("user");
        //Session登陆校验失败
        if(user == null)
        {
            this.fillNewsPageContent(model, newsId);
            model.addAttribute("replyError", "请先登陆!");
            return "news";
        }
        //登陆校验成功
        else
        {
            newsReplyFormBean.setContent(KeywordReplaceUtil.HTMLTageFilter(newsReplyFormBean.getContent()));

            //将评论信息插入数据库
            userService.addNewsReply(newsReplyFormBean, (long)newsId, user.getUserId());

            //组装重定向URL
            return  "redirect:news?id=" + newsId;
        }
    }
}

velocity里的表单

<form role="form" action="news" method="post" id="form" onsubmit="return check();">
    <input type="text" class="sr-only" name="newsId" value="${news.newsId}" />
    <div class="form-group">
        <label class="control-label sr-only" for="content"></label>
        #springBind("newsReplyFormBean.content")
        <textarea name="content" class="form-control" id="content" placeholder="说点什么..."></textarea>
        <p class="help-block" style="color: red" id="reply_help"></p>
        <p class="help-block" style="color: red">$!{replyError}</p>
    </div>
    <input type="submit" value="提交" />
</form>

还有个问题，不知道应该怎样看到这类错误的错误日志

Answer 1

@Validated 确认一下校验规则是否满足。错误日志如有有Exception在控制台或者localhost_access_xxxx.log日志中都可以看到。