LazyInitialization Exceptions with Webflow 1.3.4 and Shiro 1.1-SNAPSHOT

Hi Guys
Trying to perform a simple web flow.

here is the class

Code:

---

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:

Code:

---

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

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

Code:

---

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.

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

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.

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:

Code:

---

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

---

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

Code:

---

def createRuleFlow =
{
    setProperties
    {
        ...
    }
}

---

then I should do the wrapping like:

Code:

---

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!

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.