jsp - Liferay Portlet Taglib Cast 异常

Question

这是我在 Liferay Portal 6.0.6 中尝试运行 portlet 时得到的堆栈跟踪。

有人知道发生了什么事吗？

12:40:00,146 ERROR [PortletServlet:96] javax.portlet.PortletException: javax.servlet.ServletException: javax.servlet.jsp  .JspException: com.liferay.taglib.aui.LayoutTag cannot be cast to javax.servlet.jsp.tagext.Tag  javax.portlet.PortletException: javax.servlet.ServletException: javax.servlet.jsp.JspException: com.liferay.taglib.aui.L  ayoutTag cannot be cast to javax.servlet.jsp.tagext.Tag    at com.liferay.portlet.PortletRequestDispatcherImpl.include(PortletRequestDispatcherImpl.java:110)    at org.springframework.web.portlet.DispatcherPortlet.doRender(DispatcherPortlet.java:1137)    at org.springframework.web.portlet.DispatcherPortlet.render(DispatcherPortlet.java:1092)    at org.springframework.web.portlet.DispatcherPortlet.doRenderService(DispatcherPortlet.java:755)    at org.springframework.web.portlet.FrameworkPortlet.processRequest(FrameworkPortlet.java:522)    at org.springframework.web.portlet.FrameworkPortlet.doDispatch(FrameworkPortlet.java:470)    at javax.portlet.GenericPortlet.render(GenericPortlet.java:233)    at com.liferay.portlet.FilterChainImpl.doFilter(FilterChainImpl.java:101)    at com.liferay.portal.kernel.portlet.PortletFilterUtil.doFilter(PortletFilterUtil.java:64)    at com.liferay.portal.kernel.servlet.PortletServlet.service(PortletServlet.java:92)    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.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)    at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:551)    at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:488)    at com.liferay.portlet.InvokerPortletImpl.invoke(InvokerPortletImpl.java:638)    at com.liferay.portlet.InvokerPortletImpl.invokeRender(InvokerPortletImpl.java:723)    at com.liferay.portlet.InvokerPortletImpl.render(InvokerPortletImpl.java:425)    at org.apache.jsp.html.portal.render_005fportlet_jsp._jspService(render_005fportlet_jsp.java:1440)    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)    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.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)    at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:551)    at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:488)    at com.liferay.portal.util.PortalImpl.renderPortlet(PortalImpl.java:3740)    at com.liferay.portal.util.PortalUtil.renderPortlet(PortalUtil.java:1180)    at com.liferay.portlet.layoutconfiguration.util.RuntimePortletUtil.processPortlet(RuntimePortletUtil.java:160)    at com.liferay.portlet.layoutconfiguration.util.RuntimePortletUtil.processPortlet(RuntimePortletUtil.java:94)    at com.liferay.portlet.layoutconfiguration.util.RuntimePortletUtil.processTemplate(RuntimePortletUtil.java:256)    at com.liferay.portlet.layoutconfiguration.util.RuntimePortletUtil.processTemplate(RuntimePortletUtil.java:181)    at org.apache.jsp.html.portal.layout.view.portlet_jsp._jspService(portlet_jsp.java:821)    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)    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.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)    at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:551)    at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:488)    at com.liferay.portal.action.LayoutAction.includeLayoutContent(LayoutAction.java:370)    at com.liferay.portal.action.LayoutAction.processLayout(LayoutAction.java:629)    at com.liferay.portal.action.LayoutAction.execute(LayoutAction.java:232)    at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)    at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)    at com.liferay.portal.struts.PortalRequestProcessor.process(PortalRequestProcessor.java:153)    at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)    at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)    at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)    at com.liferay.portal.servlet.MainServlet.callParentService(MainServlet.java:508)

Answer 1

像这样的堆栈跟踪通常来自两次出现在类路径中的类。我什至看到过一次“com.something.SomeClass cannot be cast to java.lang.Object”——当时有人设法在类路径上同时获得两个 rt.jar(古代历史)。

检查 servlet api 或 jsp api，它们不应该在您的 webapp 中，而只能在 tomcat(这似乎是您正在使用的)自带的全局类路径中。如果不是这样，请检查包含也包含在全局类路径中的类的任何其他 jar。

并基于Troubleshooting java.lang.AbstractMethodError in portlet development你确实有一些类路径问题。