TOMCAT问题;严重: 
Servlet.service() for servlet jsp threw exception我在JSP中用了struts标签,出现如下状况: 
 严重:   Servlet.service()   for   servlet   jsp   threw   exception  
javax.servlet.jsp.JspException:   No   selector   attribute   (cookie/header/name/parameter)   was   specified 
 	at   org.apache.struts.taglib.logic.PresentTag.condition(PresentTag.java:163) 
 	at   org.apache.struts.taglib.logic.NotPresentTag.condition(NotPresentTag.java:93) 
 	at   org.apache.struts.taglib.logic.ConditionalTagBase.doStartTag(ConditionalTagBase.java:218) 
 	at   org.apache.jsp.Welcome_jsp._jspx_meth_logic_notPresent_0(org.apache.jsp.Welcome_jsp:203) 
 	at   org.apache.jsp.Welcome_jsp._jspService(org.apache.jsp.Welcome_jsp:97) 
 	at   org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97) 
 	at   javax.servlet.http.HttpServlet.service(HttpServlet.java:802) 
 	at   org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:322) 
 	at   org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291) 
 	at   org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241) 
 	at   javax.servlet.http.HttpServlet.service(HttpServlet.java:802) 
 	at   org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252) 
 	at   org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) 
 	at   org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213) 
 	at   org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178) 
 	at   org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126) 
 	at   org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105) 
 	at   org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107) 
 	at   org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148) 
 	at   org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856) 
 	at   org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:744) 
 	at   org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527) 
 	at   org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80) 
 	at   org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684) 
 	at   java.lang.Thread.run(Thread.java:595)   
------解决方案--------------------用logic标签测试一下list对象是否存在 
 List list = ?????????
我的异常网推荐解决方案:Servlet.service() for servlet default threw exception,http://www.aiyiweb.com/eclipse/181756.html