LazyInitialization Exceptions with Webflow 1.3.4 and Shiro 1.1-SNAPSHOT

[deuseks]

Hi Guys
Trying to perform a simple web flow.

here is the class

 class RegistrationController {

    static allowedMethods = [save: "POST", update: "POST", delete: "POST", register: "POST", register: "GET"]

    def index = {
        redirect(action:"register")
    }//end index screen

    //renders the menu of the page - or the landing page for this controller
    def menu = {
        chain(action:register,model: [personInstance: new Person()])
    }//end show registration menu

   
    // a web flow for registering a new student
    def registerFlow = {
       
        createStudent {
            //if create button is clicked
            log.debug('Entering createStudent')

            on("create")
            {
                log.debug('inside on create')

                def personInstance = new Person(params)
                if (!personInstance.validate()) {
                    flow.student = personInstance
                }
                else
                {
                    flash.message = "${message(code: 'minimalist.created.message', args: [RegistrationSchedule])}"
                    flow.student = personInstance
                    return error()
                }
            	   
            }.to "registerStudent"
            
            //if cancel button is clicked
            on("cancel")
            {
                log.debug('inside on cancel')

                redirect( action:"menu")
            }
        }//create student
       
        registerStudent{
            on("register")
            {
                def registrationInstance = new RegistrationSchedule(params)
                if (!registrationInstance.validate()) {
            	    	    
                    flow.registration = registrationInstance
                    flow.student.schedules.add(registration)
                }
                else
                {
                    flash.message = "${message(code: 'minimalist.created.message', args: [RegistrationSchedule])}"
                    flow.registration = registrationInstance
                    return error()
                }
            }
            .to "verifyRegistration"
       	        
            //if back button is clicked
            on("back").to "create"
               
            //if cancel button is clicked
            on("cancel")
            {
                redirect( action:"menu")
            }
        }//register student
       
        verifyRegistration{
            on("finish").to "showMenu"
       	       
            //if back button is clicked
            on("back").to "create"
               
            on("cancel")
            {
                redirect( action:"menu")
            }
        }//print registration
       
        showMenu {
            redirect( action:"menu")
        }

     
    }//registration flow

  
}

and I get this exception when I attempt to go to the first node on the flow:

2010-08-16 14:17:17,379 [http-8080-2] ERROR errors.GrailsExceptionResolver  - failed to lazily initialize a collection of role: ShiroUser.permissions, no session or session was closed
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: ShiroUser.permissions, no session or session was closed
        at ShiroDbRealm.isPermitted(ShiroDbRealm.groovy:76)
        at ShiroDbRealm$isPermitted.call(Unknown Source)
        at org.apache.shiro.grails.RealmWrapper.isPermitted(RealmWrapper.groovy:227)
        at org.apache.shiro.grails.RealmAdapter.isPermitted(RealmAdapter.java:57)
        at org.apache.shiro.authz.ModularRealmAuthorizer.isPermitted(ModularRealmAuthorizer.java:224)
        at org.apache.shiro.mgt.AuthorizingSecurityManager.isPermitted(AuthorizingSecurityManager.java:114)
        at $Proxy9.isPermitted(Unknown Source)
        at org.apache.shiro.subject.support.DelegatingSubject.isPermitted(DelegatingSubject.java:153)
        at ShiroGrailsPlugin.accessControlMethod(ShiroGrailsPlugin.groovy:505)
        at ShiroGrailsPlugin.accessControlMethod(ShiroGrailsPlugin.groovy)
        at ShiroGrailsPlugin$_closure3_closure23.doCall(ShiroGrailsPlugin.groovy:250)
        at SecurityFilters$_closure1_closure2_closure3.doCall(SecurityFilters.groovy:13)
        at SecurityFilters$_closure1_closure2_closure3.doCall(SecurityFilters.groovy)
        at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:359)
        at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:275)
        at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90)
        at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83)
        at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:343)
        at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:272)
        at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:83)
        at org.apache.shiro.grails.SavedRequestFilter.doFilter(SavedRequestFilter.java:55)
        at java.lang.Thread.run(Thread.java:619)
2010-08-16 14:17:17,398 [http-8080-2] ERROR [Tomcat].[localhost]  - Exception Processing ErrorPage[errorCode=500, location=/grails-errorhandler]
java.lang.IllegalStateException: Cannot reset buffer after response has been committed
        at org.apache.catalina.connector.Response.resetBuffer(Response.java:691)
        at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:409)
        at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:343)
        at org.apache.catalina.core.StandardHostValve.throwable(StandardHostValve.java:287)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
        at java.lang.Thread.run(Thread.java:619)

There isn't much out there about this exception but it appears to be something that Webflow had a while ago. Has anyone else seen this ? I am on grails 1.3.3 and a little desperate.

thanks

[pledbrook]

You should be able to fix this easily. Simply wrap the code in ShiroDbRealm.isPermitted() in a transaction like so:

def isPermitted(...) {
    ShiroUser.withTransaction {
        ...
    }
}

This will ensure that a single session is created and maintained for the life of the transaction. In fact, the default realm should be doing this, so I've raised an issue.

[deuseks]

Thanks pledbrook
that worked and got it working. I wrapped the entire contents of the method with the transaction construct and the exception disappeared.

[spotlight]

I encountered the same problem this morning and found this post. This solution worked for me also. Talk about a just in time post! Many thanks.

[paulito415]

Apologies but I'm still a relative newbie to Grails / Groovy - doesn't help that somehow my STS doesn't really do any proper syntax highlighting. I've also encountered this problem in my usage of web flows but need a bit more clarification w.r.t. what @pledbrook mentioned. When you say you wrap the entire method in:

def isPermitted(...) {
    ShiroUser.withTransaction {
        ...
    }
}

I'm assuming you mean that if I had my web flow as such:

def createRuleFlow =
{
    setProperties
    {
         ...
    }
}

then I should do the wrapping like:

def isPermitted(...) {
    ShiroUser.withTransaction {
        def createRuleFlow =
        {
             setProperties
             {
                  ...
             }
        }
    }
}

But after doing that, I can't seem to access the flow any more. Does the access URL to my flow change after I do the wrapping?

Thanks!

[paulito415]

OK never mind - I did a closer look at the FAQ for Shiro and found that in the FAQ, this was mentioned:

Q: I get a LazyInitializationException when using the Shiro plugin with WebFlow. How do I fix it?

A: WebFlow actions bypass the standard GrailsOpenSessionInViewInterceptor which means that if you access the database from within a Grails filter, you won't have a Hibernate session available. This is what happens when you use the accessControl {} syntax from a filter.

Probably the best solution is to execute the database access from within a transaction, either by using withTransaction inside your realm methods, or modifying the realm to delegate to a transactional service.

I then realized the "wrapping" should be done within the conf/ShiroSecurityFilters.groovy around the "accessControl()" call. I did that and finally this was resolved.