GRAILS-3236: Hibernate session removed after subflow endpoint

Original Reporter: alpe Environment: Not Specified Version: 1.0.3 Migrated From: http://jira.grails.org/browse/GRAILS-3236

After workflow execution a NPE occures when navigating to another page. Please see the stacktrace at the bottom. This happens for me when there is any view state after the subflow call. skipping "step4" to "completed" skips the problem also.

an example flow:

def mainFlow = {
    start{
        on ("next").to "step2"
    }
    step2{
          subflow(anySubFlow1)
           on ("finished").to "step3"
    }
    step3{
          subflow(anySubFlow2)
           on ("finished").to "step4"
    }
    step4{ // page
        on("next"){
            def testObj =  new AnyThing(anyText:'blabla_'+System.currentTimeMillis())
            testObj.save()
           flow.anyThing = testObj
        }.to "completed"
    }
       completed()
}

i did some debugging and located the session-remove in SessionAwareHibernateFlowExecutionListener.sessionEnded. the "isPersistenceContext" condition is true for any webflow (see FlowBuilder, 105 ).

Nested persistenceContexts with shared hibernate sessions (see SessionAwareHibernateFlowExecutionListener.sessionCreated) are a problem. But i also found: GRAILS-2453 GRAILS-2428

I am new to webflow but adding a session.isRoot()-condition in SessionAwareHibernateFlowExecutionListener.sessionEnded fixed it. if (session.isRoot() && isPersistenceContext(session.getDefinition())) {...

Alternative a fix could be located in the FlowBuilder, disabling persistenceContext for subflows.

java.lang.NullPointerException at org.codehaus.groovy.grails.orm.hibernate.support.GrailsOpenSessionInViewInterceptor.postHandle(GrailsOpenSessionInViewInterceptor.java:64) at org.springframework.web.servlet.handler.WebRequestHandlerInterceptorAdapter.postHandle(WebRequestHandlerInterceptorAdapter.java:61) at org.codehaus.groovy.grails.web.servlet.GrailsDispatcherServlet.doDispatch(GrailsDispatcherServlet.java:266) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:809) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:571) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:501) at javax.servlet.http.HttpServlet.service(HttpServlet.java:707) at javax.servlet.http.HttpServlet.service(HttpServlet.java:820) at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1098) at org.codehaus.groovy.grails.web.servlet.filter.GrailsReloadServletFilter.doFilterInternal(GrailsReloadServletFilter.java:112) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1089) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:365) at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216) at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181) at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:712) at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405) at org.mortbay.jetty.servlet.Dispatcher.forward(Dispatcher.java:268) at org.mortbay.jetty.servlet.Dispatcher.forward(Dispatcher.java:126) at org.codehaus.groovy.grails.web.util.WebUtils.forwardRequestForUrlMappingInfo(WebUtils.java:202) at org.codehaus.groovy.grails.web.util.WebUtils.forwardRequestForUrlMappingInfo(WebUtils.java:189) at org.codehaus.groovy.grails.web.mapping.filter.UrlMappingsFilter.doFilterInternal(UrlMappingsFilter.java:117) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1089) at org.codehaus.groovy.grails.web.sitemesh.GrailsPageFilter.parsePage(GrailsPageFilter.java:123) at org.codehaus.groovy.grails.web.sitemesh.GrailsPageFilter.doFilter(GrailsPageFilter.java:86) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1089) at org.codehaus.groovy.grails.web.servlet.mvc.GrailsWebRequestFilter.doFilterInternal(GrailsWebRequestFilter.java:65) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1089) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:96) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:236) at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1089) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:365) at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216) at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181) at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:712) at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405) at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139) at org.mortbay.jetty.Server.handle(Server.java:295) at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:503) at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:827) at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:511) at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:210) at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:379) at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:361) at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:442)

grails / grails-core

GRAILS-3236: Hibernate session removed after subflow endpoint #5879