Wednesday, 16 July 2014

NullPointerException while using currentDesign.getDoctype(currentStyle).toRequest(request)

All of us must have used currentDesign object (the current design object of the current page) to access the properties of design associated with the page. But once i came across a strange error while using  currentDesign object . When I tried to get currentDesign.getDoctype(currentStyle).toRequest(request);  I encountered an Null Pointer exception.
Here is the full error stack :

com.day.cq.wcm.core.impl.WCMDebugFilter Exception:  org.apache.sling.api.scripting.ScriptEvaluationException:
at org.apache.sling.scripting.core.impl.DefaultSlingScript.call(DefaultSlingScript.java:385)
at org.apache.sling.scripting.core.impl.DefaultSlingScript.eval(DefaultSlingScript.java:170)
at org.apache.sling.scripting.core.impl.DefaultSlingScript.service(DefaultSlingScript.java:456)
at org.apache.sling.engine.impl.request.RequestData.service(RequestData.java:500)
at org.apache.sling.engine.impl.filter.SlingComponentFilterChain.render(SlingComponentFilterChain.java:45)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:64)
at com.day.cq.wcm.core.impl.WCMDebugFilter.doFilterWithErrorHandling(WCMDebugFilter.java:183)
at com.day.cq.wcm.core.impl.WCMDebugFilter.doFilter(WCMDebugFilter.java:150)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:60)
at com.day.cq.wcm.core.impl.WCMComponentFilter.doFilter(WCMComponentFilter.java:219)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:60)
at org.apache.sling.engine.impl.SlingRequestProcessorImpl.processComponent(SlingRequestProcessorImpl.java:257)
at org.apache.sling.engine.impl.SlingRequestProcessorImpl.dispatchRequest(SlingRequestProcessorImpl.java:297)
at org.apache.sling.engine.impl.request.SlingRequestDispatcher.dispatch(SlingRequestDispatcher.java:216)
at org.apache.sling.engine.impl.request.SlingRequestDispatcher.include(SlingRequestDispatcher.java:103)
at com.day.cq.wcm.core.impl.WCMComponentFilter$ForwardRequestDispatcher.include(WCMComponentFilter.java:381)
at org.apache.jsp.libs.foundation.components.primary.cq.Page.Page_jsp._jspService(Page_jsp.java:106)
at org.apache.sling.scripting.jsp.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.apache.sling.scripting.jsp.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:420)
at org.apache.sling.scripting.jsp.JspServletWrapperAdapter.service(JspServletWrapperAdapter.java:59)
at org.apache.sling.scripting.jsp.JspScriptEngineFactory.callJsp(JspScriptEngineFactory.java:233)
at org.apache.sling.scripting.jsp.JspScriptEngineFactory.access$100(JspScriptEngineFactory.java:85)
at org.apache.sling.scripting.jsp.JspScriptEngineFactory$JspScriptEngine.eval(JspScriptEngineFactory.java:453)
at org.apache.sling.scripting.core.impl.DefaultSlingScript.call(DefaultSlingScript.java:358)
at org.apache.sling.scripting.core.impl.DefaultSlingScript.eval(DefaultSlingScript.java:170)
at org.apache.sling.scripting.core.impl.DefaultSlingScript.service(DefaultSlingScript.java:456)
at org.apache.sling.engine.impl.request.RequestData.service(RequestData.java:500)
at org.apache.sling.engine.impl.filter.SlingComponentFilterChain.render(SlingComponentFilterChain.java:45)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:64)
at com.day.cq.wcm.core.impl.WCMDebugFilter.doFilter(WCMDebugFilter.java:147)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:60)
at com.day.cq.wcm.core.impl.WCMComponentFilter.filterRootInclude(WCMComponentFilter.java:308)
at com.day.cq.wcm.core.impl.WCMComponentFilter.doFilter(WCMComponentFilter.java:141)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:60)
at org.apache.sling.engine.impl.SlingRequestProcessorImpl.processComponent(SlingRequestProcessorImpl.java:257)
at org.apache.sling.engine.impl.filter.RequestSlingFilterChain.render(RequestSlingFilterChain.java:49)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:64)
at com.day.cq.wcm.core.impl.warp.TimeWarpFilter.doFilter(TimeWarpFilter.java:106)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:60)
at com.day.cq.wcm.mobile.core.impl.redirect.RedirectFilter.doFilter(RedirectFilter.java:296)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:60)
at com.ankit.utils.XSSFilter.doFilter(com.ankit.utils.XSSFilter.java:40)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:60)
at com.ankit.servlet.SSOFilter.doFilter(com.ankit.servlet.SSOFilter.java:80)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:60)
at com.ankit.servlet.PermissionFilter.doFilter(com.ankit.servlet.PermissionFilter.java:120)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:60)
at org.apache.sling.engine.impl.debug.RequestProgressTrackerLogFilter.doFilter(RequestProgressTrackerLogFilter.java:59)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:60)
at com.day.cq.wcm.foundation.forms.impl.FormsHandlingServlet.doFilter(FormsHandlingServlet.java:220)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:60)
at com.day.cq.theme.impl.ThemeResolverFilter.doFilter(ThemeResolverFilter.java:76)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:60)
at org.apache.sling.i18n.impl.I18NFilter.doFilter(I18NFilter.java:117)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:60)
at com.day.cq.wcm.core.impl.WCMRequestFilter.doFilter(WCMRequestFilter.java:89)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:60)
at org.apache.sling.rewriter.impl.RewriterFilter.doFilter(RewriterFilter.java:83)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:60)
at org.apache.sling.bgservlets.impl.BackgroundServletStarterFilter.doFilter(BackgroundServletStarterFilter.java:135)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:60)
at org.apache.sling.engine.impl.SlingRequestProcessorImpl.processRequest(SlingRequestProcessorImpl.java:153)
at org.apache.sling.engine.impl.SlingMainServlet.service(SlingMainServlet.java:206)
at org.apache.felix.http.base.internal.handler.ServletHandler.doHandle(ServletHandler.java:96)
at org.apache.felix.http.base.internal.handler.ServletHandler.handle(ServletHandler.java:79)
at org.apache.felix.http.base.internal.dispatch.ServletPipeline.handle(ServletPipeline.java:42)
at org.apache.felix.http.base.internal.dispatch.InvocationFilterChain.doFilter(InvocationFilterChain.java:49)
at org.apache.felix.http.base.internal.dispatch.HttpFilterChain.doFilter(HttpFilterChain.java:33)
at org.apache.sling.i18n.impl.I18NFilter.doFilter(I18NFilter.java:117)
at org.apache.felix.http.base.internal.handler.FilterHandler.doHandle(FilterHandler.java:88)
at org.apache.felix.http.base.internal.handler.FilterHandler.handle(FilterHandler.java:76)
at org.apache.felix.http.base.internal.dispatch.InvocationFilterChain.doFilter(InvocationFilterChain.java:47)
at org.apache.felix.http.base.internal.dispatch.HttpFilterChain.doFilter(HttpFilterChain.java:33)
at com.adobe.granite.license.impl.LicenseCheckFilter.doFilter(LicenseCheckFilter.java:179)
at org.apache.felix.http.base.internal.handler.FilterHandler.doHandle(FilterHandler.java:88)
at org.apache.felix.http.base.internal.handler.FilterHandler.handle(FilterHandler.java:76)
at org.apache.felix.http.base.internal.dispatch.InvocationFilterChain.doFilter(InvocationFilterChain.java:47)
at org.apache.felix.http.base.internal.dispatch.HttpFilterChain.doFilter(HttpFilterChain.java:33)
at org.apache.sling.security.impl.ReferrerFilter.doFilter(ReferrerFilter.java:238)
at org.apache.felix.http.base.internal.handler.FilterHandler.doHandle(FilterHandler.java:88)
at org.apache.felix.http.base.internal.handler.FilterHandler.handle(FilterHandler.java:76)
at org.apache.felix.http.base.internal.dispatch.InvocationFilterChain.doFilter(InvocationFilterChain.java:47)
at org.apache.felix.http.base.internal.dispatch.HttpFilterChain.doFilter(HttpFilterChain.java:33)
at org.apache.sling.engine.impl.log.RequestLoggerFilter.doFilter(RequestLoggerFilter.java:75)
at org.apache.felix.http.base.internal.handler.FilterHandler.doHandle(FilterHandler.java:88)
at org.apache.felix.http.base.internal.handler.FilterHandler.handle(FilterHandler.java:76)
at org.apache.felix.http.base.internal.dispatch.InvocationFilterChain.doFilter(InvocationFilterChain.java:47)
at org.apache.felix.http.base.internal.dispatch.HttpFilterChain.doFilter(HttpFilterChain.java:33)
at org.apache.felix.http.base.internal.dispatch.FilterPipeline.dispatch(FilterPipeline.java:48)
at org.apache.felix.http.base.internal.dispatch.Dispatcher.dispatch(Dispatcher.java:39)
at org.apache.felix.http.base.internal.DispatcherServlet.service(DispatcherServlet.java:67)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at com.day.j2ee.servletengine.ServletRuntimeEnvironment.service(ServletRuntimeEnvironment.java:250)
at com.day.j2ee.servletengine.RequestDispatcherImpl.doFilter(RequestDispatcherImpl.java:315)
at com.day.j2ee.servletengine.RequestDispatcherImpl.service(RequestDispatcherImpl.java:334)
at com.day.j2ee.servletengine.RequestDispatcherImpl.service(RequestDispatcherImpl.java:377)
at com.day.j2ee.servletengine.ServletHandlerImpl.process(ServletHandlerImpl.java:351)
at com.day.j2ee.servletengine.HttpListener$Worker.run(HttpListener.java:625)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.sling.api.SlingException:
at org.apache.sling.scripting.jsp.jasper.servlet.JspServletWrapper.handleJspExceptionInternal(JspServletWrapper.java:563)
at org.apache.sling.scripting.jsp.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:499)
at org.apache.sling.scripting.jsp.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:451)
at org.apache.sling.scripting.jsp.JspServletWrapperAdapter.service(JspServletWrapperAdapter.java:59)
at org.apache.sling.scripting.jsp.JspScriptEngineFactory.callJsp(JspScriptEngineFactory.java:233)
at org.apache.sling.scripting.jsp.JspScriptEngineFactory.access$100(JspScriptEngineFactory.java:85)
at org.apache.sling.scripting.jsp.JspScriptEngineFactory$JspScriptEngine.eval(JspScriptEngineFactory.java:453)
at org.apache.sling.scripting.core.impl.DefaultSlingScript.call(DefaultSlingScript.java:358)
... 99 more
Caused by: java.lang.NullPointerException
at org.apache.jsp.apps.ankit.components.page.commonPageLayout.commonPageLayout_jsp._jspService(commonPageLayout_jsp.java:148)
at org.apache.sling.scripting.jsp.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.apache.sling.scripting.jsp.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:420)

Solution :

After spending hours to figured out the problem and I found out that jcr:content node of my design page was missing (/etc/designs/myDesign/jcr:content node).As there was no jcr:conent node under myDesign page because of that currentDesign.getDoctype(currentStyle) was returning null and this was the main reason of the NullPointerExcpetion/NPE. So, the moment I added the jcr:content node under myDesign page, code came back to life again.

Your comments and suggestions are welcome.