No action instance for path /leftTreeMenu could be created

报错信息：

14:12:12,484 ERROR RequestProcessor:284 - No action instance for path /leftTreeMenu could be created
java.lang.NullPointerException
 at sun.jkernel.DownloadManager.getBootClassPathEntryForClass(DownloadManager.java:891)
 at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:293)
 at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
 at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1255)
 at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1189)
 at org.apache.struts.util.RequestUtils.applicationClass(RequestUtils.java:117)
 at org.apache.struts.util.RequestUtils.applicationInstance(RequestUtils.java:143)
 at org.apache.struts.action.RequestProcessor.processActionCreate(RequestProcessor.java:280)
 at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:218)
 at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1194)
 at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

解决办法：

在struct-config.xml中 </action-mappings>标签后面加这么一句：

<controller processorClass="org.springframework.web.struts.DelegatingRequestProcessor"/>