使用了JSTL的jsp访问tomcat是报错：
<%@page contentType="text/html;charset=UTF-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<html><head>
<title>My Tag</title></head>
<body>
<c:set target="${product}" property="pname" value="苹果iPhone4手机"/>
<c:out value="${sessionScope.product.pname}"/>
<c:set target="${product}" property="pname"><br>
OLYMPUS数码相机
</c:set>
<c:out value="${product.pname}"/>
</body>
</html>
严重: Servlet.service() for servlet [jsp] in context with path [/firstWeb] threw exception [javax.servlet.ServletException: javax.servlet.jsp.JspTagException] with root cause
javax.servlet.jsp.JspTagException
at org.apache.taglibs.standard.tag.common.core.SetSupport.doEndTag(SetSupport.java:216)
at org.apache.jsp.SetDemo_jsp._jspx_meth_c_005fset_005f0(SetDemo_jsp.java:152)
at org.apache.jsp.SetDemo_jsp._jspService(SetDemo_jsp.java:98)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439)
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.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:1082)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:623)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2517)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2506)
at java.util.concurrent.ThreadPoolExecutor$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:619)
2016-7-25 16:19:56 org.apache.catalina.core.StandardServer await
信息: A valid shutdown command was received via the shutdown port. Stopping the Server instance.
2016-7-25 16:19:56 org.apache.coyote.AbstractProtocol pause
信息: Pausing ProtocolHandler ["http-apr-80"]
2016-7-25 16:19:56 org.apache.coyote.AbstractProtocol pause
信息: Pausing ProtocolHandler ["ajp-apr-8009"]
2016-7-25 16:19:57 org.apache.catalina.core.StandardService stopInternal
信息: Stopping service Catalina
2016-7-25 16:19:57 org.apache.catalina.core.ApplicationContext log
信息: SessionListener: contextDestroyed()
2016-7-25 16:19:57 org.apache.catalina.core.ApplicationContext log
信息: ContextListener: contextDestroyed()
2016-7-25 16:19:57 org.apache.coyote.AbstractProtocol stop
信息: Stopping ProtocolHandler ["http-apr-80"]
2016-7-25 16:19:57 org.apache.coyote.AbstractProtocol stop
信息: Stopping ProtocolHandler ["ajp-apr-8009"]
2016-7-25 16:19:57 org.apache.coyote.AbstractProtocol destroy
信息: Destroying ProtocolHandler ["http-apr-80"]
2016-7-25 16:19:57 org.apache.coyote.AbstractProtocol destroy
信息: Destroying ProtocolHandler ["ajp-apr-8009"]
有木有人知道这是什么错误？
