undefined for the type

2012-5-8 16:06:43 org.apache.catalina.startup.HostConfig deployDirectory
信息: Deploying web application directory ROOT
2012-5-8 16:06:44 org.apache.coyote.http11.Http11AprProtocol start
信息: Starting Coyote HTTP/1.1 on http-8080
2012-5-8 16:06:44 org.apache.coyote.ajp.AjpAprProtocol start
信息: Starting Coyote AJP/1.3 on ajp-8009
2012-5-8 16:06:44 org.apache.catalina.startup.Catalina start
信息: Server startup in 9662 ms
2012-5-8 16:06:57 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet jsp threw exception
org.apache.jasper.JasperException: Unable to compile class for JSP: 

An error occurred at line: 393 in the jsp file: /Club/index.jsp
The method getT() is undefined for the type ActIf
390: <img src="images/dongtai.gif" />
391: <%
392: ActIf di = new ActImpl();
393: List<Activity_list> list =(List<Activity_list>)di.getT();
394: %>
395: <ul>
396:  


Stacktrace:
at org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:92)
at org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:330)
at org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:439)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:349)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:327)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:314)
at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:592)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:317)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:861)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:579)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1584)
at java.lang.Thread.run(Unknown Source)


------解决方案--------------------
The method getT() is undefined for the type ActIf
你确定你的ActIf里面有个返回类型是List类型的getT() 方法？
------解决方案--------------------
An error occurred at line: 393 in the jsp file: /Club/index.jsp
The method getT() is undefined for the type ActIf

其实你自己也找到问题了，这句话的问题就是在index.jsp页面第393行有问题，
然后这get方法getT()在类ActIf没有被定义。你可以看一看类ActIf里面t这个属性是否申明，并且生成了get和set方法！