我报的错误是这样的
2017-6-8 14:21:23 org.apache.catalina.core.ApplicationDispatcher invoke 严重: Servlet.service() for servlet jsp threw exception java.lang.ClassNotFoundException: de.odysseus.el.ExpressionFactoryImpl at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1892) at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1735) at javax.el.ExpressionFactory.newInstance(ExpressionFactory.java:204) at javax.el.ExpressionFactory.newInstance(ExpressionFactory.java:183) at javax.el.ExpressionFactory.newInstance(ExpressionFactory.java:89) at org.apache.jasper.compiler.PageInfo.<init>(PageInfo.java:79) at org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:111) at org.apache.jasper.compiler.Compiler.compile(Compiler.java:374) at org.apache.jasper.compiler.Compiler.compile(Compiler.java:354) at org.apache.jasper.compiler.Compiler.compile(Compiler.java:341) at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:662) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:364) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:747) at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:485) at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:410) at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:337) at com.jfinal.render.JspRender.render(JspRender.java:67) at com.jfinal.core.ActionHandler.handle(ActionHandler.java:97) at com.jfinal.ext.handler.ContextPathHandler.handle(ContextPathHandler.java:47) at com.jfinal.core.JFinalFilter.doFilter(JFinalFilter.java:72) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:218) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:442) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1083) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:640) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:662) 06-08 14:21:23[ERROR]/HomePage/index com.jfinal.render.RenderException: org.apache.jasper.JasperException: Unable to compile class for JSP at com.jfinal.render.JspRender.render(JspRender.java:69) at com.jfinal.core.ActionHandler.handle(ActionHandler.java:97) at com.jfinal.ext.handler.ContextPathHandler.handle(ContextPathHandler.java:47) at com.jfinal.core.JFinalFilter.doFilter(JFinalFilter.java:72) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:218) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:442) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1083) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:640) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:662) Caused by: org.apache.jasper.JasperException: Unable to compile class for JSP at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:677) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:364) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:747) at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:485) at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:410) at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:337) at com.jfinal.render.JspRender.render(JspRender.java:67) ... 20 more Caused by: javax.el.ELException: Could not find expression factory class at javax.el.ExpressionFactory.newInstance(ExpressionFactory.java:209) at javax.el.ExpressionFactory.newInstance(ExpressionFactory.java:183) at javax.el.ExpressionFactory.newInstance(ExpressionFactory.java:89) at org.apache.jasper.compiler.PageInfo.<init>(PageInfo.java:79) at org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:111) at org.apache.jasper.compiler.Compiler.compile(Compiler.java:374) at org.apache.jasper.compiler.Compiler.compile(Compiler.java:354) at org.apache.jasper.compiler.Compiler.compile(Compiler.java:341) at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:662) ... 31 more Caused by: java.lang.ClassNotFoundException: de.odysseus.el.ExpressionFactoryImpl at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1892) at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1735) at javax.el.ExpressionFactory.newInstance(ExpressionFactory.java:204) ... 39 more可能是tomcat服务器版本不对应，我之前项目的jdk由1.7换到了1.6版本，不过tomcat还是用的之前的7.0，所以报了这个错误，把tomcat换到了6.0就好了。
一般来说tomcat5对应jdk1.5，tomcat6对应jdk1.6，tomcat7对应jdk1.7，tomcat8对应jdk1.8
