If possible, JSPs should be avoided. There are several known limitations when using them with embedded servlet containers.

尽可能避免使用jsp
嵌入式servlet容器使用jsp有一些限制

https://docs.spring.io/spring-boot/docs/2.0.0.RELEASE/reference/html/boot-features-developing-web-applications.html#boot-features-jsp-limitations

JSP Limitations

When running a Spring Boot application that uses an embedded servlet container 
(and is packaged as an executable archive), there are some limitations in the JSP support.

With Tomcat, it should work if you use war packaging. 
That is, an executable war works and is also deployable to a standard container (not limited to, but including Tomcat). 
An executable jar does not work because of a hard-coded file pattern in Tomcat.

With Jetty, it should work if you use war packaging. 
That is, an executable war works, and is also deployable to any standard container.

Undertow does not support JSPs.

Creating a custom error.jsp page does not override the default view for error handling. 
Custom error pages should be used instead.

打成war包， 部署到标准容器可以正常工作

Undertow不支持 jsp

创建自定义error.jsp页面不会覆盖用于错误处理的默认视图。应该使用自定义错误页面。

https://github.com/spring-projects/spring-boot/tree/v2.0.0.RELEASE/spring-boot-samples/spring-boot-sample-web-jsp