ClassNotFoundException突然地蚀

Question

i am using eclipse 3.4.1, jre6, tomcat 6, jsf 1.2 and rich faces 3. Application was working just fine when all of a sudden it started generating following error in browser.

Sorry, a fatal error has occurred. The error has been logged.Please log in again. 

while the console in eclipse says:-

SEVERE: Servlet.service() for servlet jsp threw exception
java.lang.ClassNotFoundException: org.college.ui.bean.SearchUserBean
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1680)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at org.apache.myfaces.shared_impl.util.ClassUtils.classForName(ClassUtils.java:141)
at org.apache.myfaces.shared_impl.util.ClassUtils.simpleClassForName(ClassUtils.java:160)
at org.apache.myfaces.shared_impl.util.ClassUtils.newInstance(ClassUtils.java:268)
at org.apache.myfaces.config.ManagedBeanBuilder.buildManagedBean(ManagedBeanBuilder.java:49)
at org.apache.myfaces.el.VariableResolverImpl.resolveVariable(VariableResolverImpl.java:314)
at org.apache.myfaces.trinidadinternal.el.TrinidadVariableResolver.resolveVariable(TrinidadVariableResolver.java:54)
at org.apache.myfaces.el.ValueBindingImpl$ELVariableResolver.resolveVariable(ValueBindingImpl.java:570)
at org.apache.commons.el.NamedValue.evaluate(NamedValue.java:124)
at org.apache.commons.el.ComplexValue.evaluate(ComplexValue.java:140)
at org.apache.myfaces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:386)
at javax.faces.component.UIOutput.getValue(UIOutput.java:80)
at org.apache.myfaces.shared_impl.renderkit.RendererUtils.getStringValue(RendererUtils.java:223)
at org.apache.myfaces.shared_impl.renderkit.html.HtmlTextRendererBase.renderInput(HtmlTextRendererBase.java:135)
at org.apache.myfaces.shared_impl.renderkit.html.HtmlTextRendererBase.encodeEnd(HtmlTextRendererBase.java:53)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:539)
at org.apache.myfaces.shared_impl.renderkit.RendererUtils.renderChild(RendererUtils.java:419)
at org.apache.myfaces.shared_impl.renderkit.html.HtmlGridRendererBase.renderChildren(HtmlGridRendererBase.java:229)
at org.apache.myfaces.shared_impl.renderkit.html.HtmlGridRendererBase.encodeEnd(HtmlGridRendererBase.java:101)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:539)
at org.apache.myfaces.shared_impl.renderkit.RendererUtils.renderChild(RendererUtils.java:419)
at org.apache.myfaces.shared_impl.renderkit.html.HtmlGridRendererBase.renderChildren(HtmlGridRendererBase.java:229)
at org.apache.myfaces.shared_impl.renderkit.html.HtmlGridRendererBase.encodeEnd(HtmlGridRendererBase.java:101)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:539)
at org.apache.myfaces.shared_impl.renderkit.RendererUtils.renderChild(RendererUtils.java:419)
at org.apache.myfaces.shared_impl.renderkit.RendererUtils.renderChildren(RendererUtils.java:400)
at org.apache.myfaces.shared_impl.renderkit.html.HtmlGroupRendererBase.encodeEnd(HtmlGroupRendererBase.java:78)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:539)
at javax.faces.webapp.UIComponentTag.encodeEnd(UIComponentTag.java:498)
at javax.faces.webapp.UIComponentTag.doEndTag(UIComponentTag.java:366)
at org.apache.myfaces.shared_impl.taglib.UIComponentBodyTagBase.doEndTag(UIComponentBodyTagBase.java:57)
at org.apache.jsp.pages.login_jsp._jspx_meth_h_005fpanelGroup_005f0(login_jsp.java:254)
at org.apache.jsp.pages.login_jsp._jspx_meth_h_005fform_005f0(login_jsp.java:199)
at org.apache.jsp.pages.login_jsp._jspx_meth_f_005fview_005f0(login_jsp.java:165)
at org.apache.jsp.pages.login_jsp._jspService(login_jsp.java:129)
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:388)
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.processRequest(ApplicationDispatcher.java:436)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302)
at org.apache.myfaces.context.servlet.ServletExternalContextImpl.dispatch(ServletExternalContextImpl.java:419)
at org.apache.myfaces.trinidad.context.ExternalContextDecorator.dispatch(ExternalContextDecorator.java:43)
at org.apache.myfaces.trinidad.context.ExternalContextDecorator.dispatch(ExternalContextDecorator.java:43)
at org.apache.myfaces.trinidadinternal.context.FacesContextFactoryImpl$OverrideDispatch.dispatch(FacesContextFactoryImpl.java:260)
at org.apache.myfaces.application.jsp.JspViewHandlerImpl.renderView(JspViewHandlerImpl.java:211)
at org.apache.myfaces.trinidadinternal.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:182)
at org.apache.myfaces.lifecycle.RenderResponseExecutor.execute(RenderResponseExecutor.java:41)
at org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:132)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:140)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:147)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
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.processRequest(ApplicationDispatcher.java:436)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302)
at org.apache.jasper.runtime.PageContextImpl.doForward(PageContextImpl.java:709)
at org.apache.jasper.runtime.PageContextImpl.forward(PageContextImpl.java:680)
at org.apache.jsp.index_jsp._jspService(index_jsp.java:60)
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:388)
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.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:291)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)

Thanks for patience. plz tell me what could be the possible cause of this. i have checked my faces.config and beans and the jsp page etc. every thing is well bind. And the fact that it was working just fine and all of a sudden this error generated is weird and spooky.

Thanks in advance. Plz answer before closing the question or yelling at me for being so naive.

Answer 1

This is a typical problem deploying applicaitons in eclipse and tomcat. As shazin said you can do Project-Clean Maven clean etc..

This should be enough, but in my case, sometimes this doesn't solve the problem.

If it doesn't work try to go to SERVER tab, right click on the tomcat server and do a "Clean". Tomcat will publish the projects again.

Answer 2

做一个Project -> Clean ，如果您使用的是Maven，请同时做一个Maven清理。