Unable to compile class for jsp problem solution in eclipse

Yesterday I encountered a problem that eclipse could not compile jsp. At first, I thought that too many lines of code caused memory overflow. Then I deleted the blank lines in jsp, shortened the number of lines of code, and reported this error. Later I found out that it was server configuration. The problem

Solution: add to the web.xml file under Tomcat

<init-param> 
       <param-name>mappedfile</param-name> 
       <param-value>false</param-value> 
 </init-param>