java.lang.NullPointerException at edu.illinois.webservices.systemscreen.BaseSystemScreenFactory2.getSystemScreen(BaseSystemScreenFactory2.java:341) at edu.illinois.webservices.systemscreen.SystemScreenFactory2.transform(SystemScreenFactory2.java:192) at edu.illinois.webservices.systemscreen.SystemScreenFactory2.transform(SystemScreenFactory2.java:106) at edu.illinois.webservices.blog.servlet.ViewServlet.doPost(ViewServlet.java:358) at edu.illinois.webservices.blog.servlet.ViewServlet.doGet(ViewServlet.java:67) at javax.servlet.http.HttpServlet.service(HttpServlet.java:529) at javax.servlet.http.HttpServlet.service(HttpServlet.java:623) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:209) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:178) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153) at org.apache.catalina.filters.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:115) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:178) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:153) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:168) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:481) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:130) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) at org.apache.coyote.ajp.AjpProcessor.service(AjpProcessor.java:424) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:928) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1794) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52) at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:750)