报错如下：
Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Circular view path [jxsr2]: would dispatch back to the current handler URL [/jxsr2] again. Check your ViewResolver setup! (Hint: This may be the result of an unspecified view, due to default view name generation.)] with root cause
解决方法：
加上@ResponseBody
参考链接：
【1】https://blog.csdn.net/weixin_44259720/article/details/103185972
标签：exception,jxsr2,view,path,dispatcherServlet,Servlet,Circular From： https://www.cnblogs.com/ReturnOfTheKing/p/17244383.html