Today, I wrote the beginning of the shopping project of Shangxuetang, and an error occurred:
org.apache.jasper.JasperException: Unable to compile class for JSP
某类不可以被引用（这里把日志翻译了一下）
Stacktrace:
org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:92)
org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:330)
org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:439)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:334)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:312)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:299)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:586)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:317)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java: 856)
At first, I thought it was caused by the lack of jars. Later, I copied the same jar package as the shopping example project, but restarting is still not enough.
Later, I saw an article saying that he also encountered this problem when he transplanted, and then I re-checked the path to compile the class, only to find that there is no classes folder under WEB-INF, and of course, the compiled class was not placed in under this folder.
Solution:
Create a classes folder under WEB-INF, and then set it in properties as shown in the attachment
Analyze the reasons:
In fact, many problems can be found from the source, such as this problem. In fact, the final class file is read.