WARN:oejw.WebAppContext:Thread-5113: Failed startup of context o.e.j.w.WebAppContext- java.lang.NullPointerException

Question

Our project has two servers if one server is closed then it should connect to the another one. But I'm getting this error while doing so. It is not connecting either.

WARN:oejw.WebAppContext:Thread-5113: Failed startup of context o.e.j.w.WebAppContext@1b14e897{/,file:///cots/ENet/webserver/webapps/cgiAdapter/,UNAVAILABLE}+ java.lang.NullPointerException+
at org.eclipse.jetty.webapp.MetaInfConfiguration.scanJars(MetaInfConfiguration.java:143)+
at org.eclipse.jetty.webapp.MetaInfConfiguration.preConfigure(MetaInfConfiguration.java:102)+
at org.eclipse.jetty.webapp.WebAppContext.preConfigure(WebAppContext.java:506)+ at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:544)+
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)+ at geh.appserver.webserver.WebServerManager.systemInfoChanged(WebServerManager.java:681)+
at geh.appserver.AppServerController.sendSystemInformation(AppServerController.java:12344)+ at geh.appserver.AppServerBrokerImpl.sendSystemInformation(AppServerBrokerImpl.java:966)+
at geh.agent.XaDynamicDataManager$48.run(cd ME:13666) java.lang.IllegalStateException: STARTED

Here's the code:

public void systemInfoChanged(boolean inStandbyMode) {
    logger.log(Logger.INFO, "systemInfoChanged - inStandbyMode = " + inStandbyMode);

    for (Iterator i = connectorList.iterator(); i.hasNext();) {
        WebServerConnector wsc = (WebServerConnector) i.next();

        if (inStandbyMode) {
            logger.log(Logger.DEBUG, "SHUTDOWN SISO CONTEXTS FOR ADDRESS [ " + wsc.getAddress() + " ] PORT [ "
                    + wsc.getPort() + " ]");

            if (sisoContexts != null) 
            {
                for (int c = 0; c < sisoContexts.getHandlers().length; c++) {
                    try {

                        sisoContexts.getHandlers()[c].stop();
                    } catch (Exception e) {
                        logger.log(Logger.ERROR, "Error occurred while stopping handler");
                        e.printStackTrace();
                    }
                    allContexts.removeHandler(sisoContexts.getHandlers()[c]);
                }
                sisoContexts = new ContextHandlerCollection();
                sisoContexts.setHandlers(new Handler[]  {}); //empty handler collection

                sisoUp = false;
            }
        } else {
            logger.log(Logger.DEBUG, "STARTUP SISO CONTEXTS FOR ADDRESS [ " + wsc.getAddress() + " ] PORT [ "
                    + wsc.getPort() + " ]");

            WebAppContext cgiContext = new WebAppContext();

            cgiContext.setDescriptor(root + fileSeparator + "webapps" + fileSeparator + "cgiAdapter" + "/WEB-INF/web.xml");
            cgiContext.setResourceBase(root + fileSeparator + "webapps" + fileSeparator + "cgiAdapter");                
            cgiContext.setAttribute(
                    "org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern",
                    ".*/[^/]*servlet-api-[^/]*\\.jar$|.*/javax.servlet.jsp.jstl-.*\\.jar$|.*/[^/]*taglibs.*\\.jar$" );

            if (!sisoUp) {
                try {
                    cgiContext.start(); // start handler before adding back
                                        // to the server
                    allContexts.addHandler(cgiContext);
                    sisoContexts.addHandler(cgiContext);
                    sisoUp = true;
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }

        }
    }
}