title: NPE in CSRFGuard
body: <p>I want to protect my app from csrf, so I add owasp.csrf.jar and configure my app as described <a href="https://github.com/esheri3/OWASP-CSRFGuard" rel="nofollow">here</a> Then I add hidden field to one of my forms with csrf token tags, like this:</p>
  
  <pre><code>&lt;input type="hidden" name="&lt;csrf:token-name/&gt;" value="&lt;csrf:token-value/&gt;" /&gt;
  </code></pre>
  
  <p>but when my page is rendering I get NPE in <strong>TokenNameTag.java</strong></p>
  
  <p>What have I missed?</p>
  
  <p><strong>UPDATE</strong></p>
  
  <p>The stacktrace:</p>
  
  <pre><code>2013-04-15 10:46:49,985 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[localhost].[/myapp].[jsp]]  Servlet.service() for servlet jsp threw exception
  java.lang.NullPointerException
      at org.owasp.csrfguard.tag.TokenNameTag.doStartTag(TokenNameTag.java:45)
      at org.apache.jsp.struts.config.configurationMain_jsp._jspx_meth_csrf_005ftoken_002dname_005f0(configurationMain_jsp.java:7405)
      at org.apache.jsp.struts.config.configurationMain_jsp._jspx_meth_html_005fform_005f7(configurationMain_jsp.java:6812)
      at org.apache.jsp.struts.config.configurationMain_jsp._jspx_meth_logic_005fmatch_005f3(configurationMain_jsp.java:6695)
      at org.apache.jsp.struts.config.configurationMain_jsp._jspService(configurationMain_jsp.java:1712)
      at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
      at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:387)
      at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
      at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
      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:687)
      at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:469)
      at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:403)
      at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:301)
      at org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1069)
      at org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:455)
      at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:279)
      at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
      at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:507)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
      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:687)
      at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:469)
      at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:403)
      at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:301)
      at org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1069)
      at org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:455)
      at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:279)
      at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
      at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:507)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
      at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
      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.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
      at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
      at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:179)
      at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)
      at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
      at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
      at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157)
      at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
      at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:241)
      at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
      at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:580)
      at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
      at java.lang.Thread.run(Thread.java:662)
  </code></pre>