Spring Whitelabel Error Page： This application has no explicit mapping for /error, so you are seeing

springboot的案例 

https://www.cnblogs.com/du001011/p/13532859.html

后端有相应，前端没有页面生成报404错误，jsp技术的使用。

https://blog.csdn.net/qijingpei/article/details/79188495