Error java NullPointerException at org.apache.myfaces.taglib.core.ViewTag.doStartTag(ViewTag.java:75)

Question

I'm trying to stabilize a web project made in Java with weblogic. When I start the project, I get the following error:

    java.lang.NullPointerException
at org.apache.myfaces.taglib.core.ViewTag.doStartTag(ViewTag.java:75)
at jsp_servlet.__login._jspService(__login.java:128)
at weblogic.servlet.jsp.JspBase.service(JspBase.java:35)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:280)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:254)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:136)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:346)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:243)
at weblogic.servlet.internal.RequestDispatcherImpl.invokeServlet(RequestDispatcherImpl.java:587)
at weblogic.servlet.internal.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:273)
at com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:568)
at com.sun.faces.application.view.JspViewHandlingStrategy.executePageToBuildView(JspViewHandlingStrategy.java:363)
at com.sun.faces.application.view.JspViewHandlingStrategy.buildView(JspViewHandlingStrategy.java:153)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:99)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:594)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:280)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:254)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:136)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:346)
at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:25)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)
at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:100)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)
at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:147)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)
at weblogic.servlet.internal.RequestEventsFilter.doFilter(RequestEventsFilter.java:27)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3436)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3402)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)
at weblogic.servlet.provider.WlsSubjectHandle.run(WlsSubjectHandle.java:57)
at weblogic.servlet.internal.WebAppServletContext.doSecuredExecute(WebAppServletContext.java:2285)
at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2201)
at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2179)
at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1572)
at weblogic.servlet.provider.ContainerSupportProviderImpl$WlsRequestExecutor.run(ContainerSupportProviderImpl.java:255)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:311)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:263)

I have read in other stackoverflow posts with the same problem, and the solution is to enter the xml and the tag filtername-urlpattern place the extension * .jsf, since it executes componenetes. * Jsf within the .jsp. But this was well configured, and it still does not work. web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
   <context-param>
      <param-name>javax.faces.STATE_SAVING_METHOD</param-name>
      <param-value>server</param-value>
   </context-param>
   <context-param>
      <param-name>org.apache.myfaces.ALLOW_JAVASCRIPT</param-name>
      <param-value>true</param-value>
   </context-param>
   <context-param>
      <param-name>org.apache.myfaces.PRETTY_HTML</param-name>
      <param-value>true</param-value>
   </context-param>
   <context-param>
      <param-name>org.apache.myfaces.DETECT_JAVASCRIPT</param-name>
      <param-value>false</param-value>
   </context-param>
   <context-param>
      <param-name>org.apache.myfaces.AUTO_SCROLL</param-name>
      <param-value>true</param-value>
   </context-param>
   <servlet>
      <servlet-name>Faces Servlet</servlet-name>
      <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
      <load-on-startup>1</load-on-startup>
   </servlet>
   <servlet>
      <description>Encargado de realizar la validacion de login</description>
      <servlet-name>LoginServlet</servlet-name>
      <servlet-class>com.proycomp.recaudo.servicios.LoginServlet</servlet-class>
      <load-on-startup>1</load-on-startup>
   </servlet>

   <listener>
      <listener-class>com.proycomp.recaudo.servicios.ContextListener</listener-class>
   </listener>

   <servlet-mapping>
      <servlet-name>LoginServlet</servlet-name>
      <url-pattern>/loginServlet</url-pattern>
   </servlet-mapping>   

   <servlet-mapping>
      <servlet-name>Faces Servlet</servlet-name>
      <url-pattern>*.jsf</url-pattern>
   </servlet-mapping> 


   <filter>
      <filter-name>MyFacesExtensionsFilter</filter-name>
      <filter-class>org.apache.myfaces.webapp.filter.ExtensionsFilter</filter-class>
      <init-param>
         <param-name>uploadMaxFileSize</param-name>
         <param-value>5m</param-value>
      </init-param>
      <init-param>
         <param-name>uploadThresholdSize</param-name>
         <param-value>100k</param-value>
      </init-param>
   </filter>


   <filter-mapping>
      <filter-name>MyFacesExtensionsFilter</filter-name>
      <servlet-name>Faces Servlet</servlet-name>
   </filter-mapping>
   <filter-mapping>
      <filter-name>MyFacesExtensionsFilter</filter-name>
      <url-pattern>/faces/myFacesExtensionResource/*</url-pattern>
   </filter-mapping>
   <filter-mapping>
      <filter-name>MyFacesExtensionsFilter</filter-name>
      <url-pattern>*.jsf</url-pattern>
   </filter-mapping>
   <session-config>
      <session-timeout>30</session-timeout>
   </session-config>
   <welcome-file-list>
      <welcome-file>index.jsp</welcome-file>
   </welcome-file-list>
   <jsp-config/>
</web-app>

Answer 1

It seemes like you are mixing JSF reference implementation Mojarra and Apache JSF implementation MyFaces together. I see classes of both in your stack trace. (org.apache.myfaces vs com.sun.faces). I guess WebLogic provides the Mojarra implementation so you should not add JSF related JARs to your web application.

If your build tool is Maven, remove myfaces-impl artifact and mark myfaces-api with <scope>provided</scope> or replace it with

<dependency>
    <groupId>javax.faces</groupId>
    <artifactId>javax.faces-api</artifactId>
    <version>YOUR_WEB_LOGICS_JSF_API_VERSION_HERE</version>
    <scope>provided</scope>
</dependency>