The error that Tomcat generated when running JSP: "Javax.servlet.servletexception:java.lang.nosuchmethoderror"

This error is actually repeated several times to compile the Java file caused, need clean operation, simply delete the work folder Tomcat under the working space, but also can be understood as their own virtual path, such as the path of the JSP I run: LOCALHOST:8080/YSW/1. JSP; At this point, simply delete the corresponding YSW file in the work folder, then recompile the Java file, and get the class file in the classes file in the Web-inf folder in WebApps's own virtual path, Classes saves the JavaBean file you need to use, which is the. class file.

The error that Tomcat generated when running JSP: "Javax.servlet.servletexception:java.lang.nosuchmethoderror"