Java method "com.bupticet.cms.web.action.ContentAction.getCategories()" threw an exception when invoked on com.bupticet.cms.web.action.ContentAction object "com.bupticet.cms.web.action.ContentAction@2034981"; see cause exception in the Java stack trace.

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FTL stack trace ("~" means nesting-related):
	- Failed at: #assign categories = action.getCatego...  [in template "WEB-INF/config/site_templates/default/category_temp/default/left_nav.ftl" at line 2, column 1]
	- Reached through: #include "left_nav.ftl"  [in template "WEB-INF/config/site_templates/default/category_temp/default/catetory.ftl" at line 12, column 5]
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Java stack trace (for programmers):
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freemarker.core._TemplateModelException: [... Exception message was already printed; see it above ...]
	at freemarker.ext.beans._MethodUtil.newInvocationTemplateModelException(_MethodUtil.java:289)
	at freemarker.ext.beans._MethodUtil.newInvocationTemplateModelException(_MethodUtil.java:252)
	at freemarker.ext.beans.SimpleMethodModel.exec(SimpleMethodModel.java:77)
	at freemarker.core.MethodCall._eval(MethodCall.java:65)
	at freemarker.core.Expression.eval(Expression.java:83)
	at freemarker.core.Assignment.accept(Assignment.java:134)
	at freemarker.core.Environment.visit(Environment.java:330)
	at freemarker.core.Environment.visit(Environment.java:336)
	at freemarker.core.Environment.include(Environment.java:2582)
	at freemarker.core.Include.accept(Include.java:171)
	at freemarker.core.Environment.visit(Environment.java:330)
	at freemarker.core.Environment.visit(Environment.java:336)
	at freemarker.core.Environment.visit(Environment.java:336)
	at freemarker.core.Environment.process(Environment.java:309)
	at freemarker.template.Template.process(Template.java:384)
	at org.apache.struts2.views.freemarker.FreemarkerResult.doExecute(FreemarkerResult.java:223)
	at org.apache.struts2.dispatcher.StrutsResultSupport.execute(StrutsResultSupport.java:193)
	at com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:372)
	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:276)
	at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:229)
	at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
	at com.filter.XssInterceptor.intercept(XssInterceptor.java:31)
	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
	at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:189)
	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:245)
	at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)
	at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:575)
	at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:81)
	at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
	at com.bupticet.filter.WrapperFilter.doFilter(WrapperFilter.java:153)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:190)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:163)
	at com.bupticet.filter.SetClientInfoFilter.doFilterInternal(SetClientInfoFilter.java:60)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at com.bupticet.filter.WrapperFilter.doFilter(WrapperFilter.java:153)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:190)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:163)
	at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:176)
	at org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:145)
	at org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:92)
	at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:381)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:190)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:163)
	at com.bupticet.clickstream.filter.VisitRecordFilter.doFilterInternal(VisitRecordFilter.java:125)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at com.bupticet.filter.WrapperFilter.doFilter(WrapperFilter.java:153)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:190)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:163)
	at com.bupticet.filter.ForceNoCacheFilter.doFilterInternal(ForceNoCacheFilter.java:98)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at com.bupticet.filter.WrapperFilter.doFilter(WrapperFilter.java:153)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:190)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:163)
	at com.bupticet.filter.WrapperFilter.doFilter(WrapperFilter.java:140)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:190)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:163)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at com.bupticet.filter.WrapperFilter.doFilter(WrapperFilter.java:153)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:190)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:163)
	at com.bupticet.filter.LoginModuleFilter.doFilterInternal(LoginModuleFilter.java:104)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at com.bupticet.filter.WrapperFilter.doFilter(WrapperFilter.java:153)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:190)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:163)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:101)
	at com.bupticet.educonfig.filter.TermConfigFilter.doFilterInternal(TermConfigFilter.java:32)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at com.bupticet.filter.WrapperFilter.doFilter(WrapperFilter.java:153)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:190)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:163)
	at com.alibaba.druid.support.http.WebStatFilter.doFilter(WebStatFilter.java:123)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:190)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:163)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:687)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:382)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:893)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1723)
	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:748)
Caused by: java.lang.StringIndexOutOfBoundsException: String index out of range: -1
	at java.lang.String.substring(String.java:1967)
	at com.bupticet.cms.web.action.ContentAction.getCategories(ContentAction.java:647)
	at sun.reflect.GeneratedMethodAccessor305.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at freemarker.ext.beans.BeansWrapper.invokeMethod(BeansWrapper.java:1505)
	at freemarker.ext.beans.SimpleMethodModel.exec(SimpleMethodModel.java:72)
	... 90 more