Unable to compile class for JSP

type Exception report

message 

description The server encountered an internal error () that prevented it from fulfilling this request.

exception 

org.apache.jasper.JasperException: Unable to compile class for JSP: 

An error occurred at line: 22 in the generated java file
The method getJspApplicationContext(ServletContext) is undefined for the type JspFactory

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:356)
	org.apache.jasper.compiler.Compiler.compile(Compiler.java:334)
	org.apache.jasper.compiler.Compiler.compile(Compiler.java:321)
	org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:592)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:328)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:389)


note The full stack trace of the root cause is available in the Apache Tomcat/6.0.33 logs.

应该是由于WEB-INF/lib下存在jsp-api.jar、servlet-api.jar，与web容器中自带的jar包冲突造成。
在Tomcat 7中，还需要删除slf4j-api-1.6.0.jar