Liferay Portlet Taglib施放异常

Question

这是我在Liferay Portal 6.0.6中运行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类路径上的类两次.我甚至看到"com.something.SomeClass无法转换为java.lang.Object"一次 - 当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,这些不应该在你的webapp中,而只是在tomcat(这似乎是你正在使用的)带来的全局类路径中.如果不是这样,请检查包含全局类路径中包含的类的任何其他jar.

基于portlet开发中的java.lang.AbstractMethodError故障排除,您确实遇到了一些类路径问题.