Servlet Error: NullPointer

An unexpected servlet error has occurred.

Stack Trace:



java.lang.NullPointerException at net.sf.saxon.value.Value.asItem(Value.java:71) at net.sf.saxon.expr.VariableReference.evaluateItem(VariableReference.java:291) at net.sf.saxon.functions.Concat.evaluateItem(Concat.java:38) at net.sf.saxon.expr.Expression.iterate(Expression.java:283) at net.sf.saxon.expr.LazyExpression.iterate(LazyExpression.java:95) at net.sf.saxon.value.MemoClosure.iterate(MemoClosure.java:89) at net.sf.saxon.value.Value.asItem(Value.java:81) at net.sf.saxon.value.Value.asItem(Value.java:71) at net.sf.saxon.expr.VariableReference.evaluateItem(VariableReference.java:291) at net.sf.saxon.functions.Matches.evaluateItem(Matches.java:70) at net.sf.saxon.expr.Expression.iterate(Expression.java:283) at net.sf.saxon.expr.Expression.effectiveBooleanValue(Expression.java:299) at net.sf.saxon.expr.FilterIterator$NonNumeric.matches(FilterIterator.java:178) at net.sf.saxon.expr.FilterIterator.getNextMatchingItem(FilterIterator.java:69) at net.sf.saxon.expr.FilterIterator.next(FilterIterator.java:49) at net.sf.saxon.expr.ContextMappingIterator.next(ContextMappingIterator.java:59) at net.sf.saxon.expr.ContextMappingIterator.next(ContextMappingIterator.java:52) at net.sf.saxon.instruct.BlockIterator.next(BlockIterator.java:44) at net.sf.saxon.expr.MappingIterator.next(MappingIterator.java:51) at net.sf.saxon.expr.ItemMappingIterator.next(ItemMappingIterator.java:39) at net.sf.saxon.functions.StringJoin.evaluateItem(StringJoin.java:56) at net.sf.saxon.expr.CastExpression.evaluateItem(CastExpression.java:278) at net.sf.saxon.instruct.SimpleContentConstructor.evaluateItem(SimpleContentConstructor.java:216) at net.sf.saxon.instruct.SimpleNodeConstructor.expandChildren(SimpleNodeConstructor.java:150) at net.sf.saxon.instruct.FixedAttribute.processLeavingTail(FixedAttribute.java:247) at net.sf.saxon.instruct.Block.processLeavingTail(Block.java:365) at net.sf.saxon.instruct.Instruction.process(Instruction.java:91) at net.sf.saxon.instruct.ElementCreator.processLeavingTail(ElementCreator.java:240) at net.sf.saxon.expr.LetExpression.processLeavingTail(LetExpression.java:405) at net.sf.saxon.instruct.Block.processLeavingTail(Block.java:365) at net.sf.saxon.instruct.Template.expand(Template.java:112) at net.sf.saxon.instruct.CallTemplate.process(CallTemplate.java:212) at net.sf.saxon.instruct.CallTemplate.processLeavingTail(CallTemplate.java:237) at net.sf.saxon.instruct.Block.processLeavingTail(Block.java:365) at net.sf.saxon.instruct.Instruction.process(Instruction.java:91) at net.sf.saxon.instruct.ElementCreator.processLeavingTail(ElementCreator.java:240) at net.sf.saxon.instruct.Template.applyLeavingTail(Template.java:98) at net.sf.saxon.instruct.ApplyTemplates.applyTemplates(ApplyTemplates.java:317) at net.sf.saxon.Controller.transformDocument(Controller.java:1705) at net.sf.saxon.Controller.transform(Controller.java:1513) at org.cdlib.xtf.crossQuery.CrossQuery.runQueryParser(CrossQuery.java:379) at org.cdlib.xtf.crossQuery.CrossQuery.apply(CrossQuery.java:200) at org.cdlib.xtf.crossQuery.CrossQuery.doGet(CrossQuery.java:153) at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) at org.cdlib.xtf.servletBase.TextServlet.service(TextServlet.java:442) at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:688) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1594) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:750)