WebFlow action bean needs AOP

[mjreged]

In my Project i use Spring WebFlow.
I have a bean defined in one of my flow.xml files

<bean id="customerActions" class="com.system.actions.CustomerAction" >
		<property name="webService" ref="customerWebService"/>
		 <property name="agentService" ref="agentClient"/>  
	</bean>

Customer Action extends MultiAction class from webflow.

Now i have a SecurityAspect class annotiated as AspectJ

@Aspect
public class SecurityAspect {		
	private SecuritySession session;
	
	@Before("@annotation(com.system.lib.Security)")
	public void checkSecurity(JoinPoint jp) throws Throwable{
		String userid = session.getUserid();
        if (userid == null) {          
            throw new SecurityException("User credentials must be present before attempting to invoke the method: "+ getMethod(jp).getName() );
        }   
        
		
	}
}

My CustomerAction contains annotation that should be intercepted by this SecurityAspect.
However that is not the case, the aspect is never executed.


I don't understand why this bean is omitted, it is spring managed.
Is it possible that webflow has its own spring managed context and my SecurityAspect lives in a separate managed context?

If someone has an opinion or knowledge on this please share.

[Marten Deinum]

With Spring AOP you can only execute external method calls. Spring Web Flow Actions have only 1 method which is externally called namly the execute methods. All other method calls are internal calls and aren't going to be proxied or executed.

[mjreged]

here is the CustomerAction
I have a public method called setup

public class CustomerAction extends MultiAction{		
	
	@Security(group="POLCUSTOMER" )
	public Event setup( RequestContext context ){
		Customer c = ((Customer)context.getConversationScope().get("customer") );
		CustomerRenderer renderer = new CustomerRenderer();		
		renderer.setCustomer(c);
		if( c != null ){
			renderer.setBusinessVisible( c.getNameType().getValue().equals("I") == false );
		}
		// help generate a Command button for transision
		String command = ((String)context.getFlashScope().get("commandFlow") );
		renderer.setFlowCommand(command);		
		context.getConversationScope().put("customerRenderer", renderer);
		
		
		
		return success();
	}

I have a create-customer-flow.xml
that invokes this public method

	 
	<start-actions>		
		<action method="setup" bean="customerActions" />
		<action method="getCustomerType" bean="customerActions" />	
		<action method="getStateList" bean="customerActions" />	
		<action method="getTitleList" bean="customerActions"/>
		<action method="getSuffixList" bean="customerActions"/>
	</start-actions>
	
	

	<start-state idref="displayForm" />

So i have to realize that all these methods cannot be intercepted by Spring AOP Aspects?

[Marten Deinum]

I have a create-customer-flow.xml that invokes this public method

It still calls the execute method, however the MultiAction uses some reflection to invoke the configured method on itself, effectivly making it an internal call.

So i have to realize that all these methods cannot be intercepted by Spring AOP Aspects?

Not with the proxy based approach. If you want to intercept those calls you will need a full AOP solution (like AspectJ) and use either load- or compile time weaving.

[mjreged]

thank you mdeinum for the swift clarification.

I understand now.

[jokrasa]

You say use AspectJ because it uses compile-time weaving...

I'm trying @AspectJ with java 5 annot. and
just trying to get it working.

I've added the configs:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="
           http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
           http://www.springframework.org/schema/aop
           http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">


    <aop:aspectj-autoproxy>
       <aop:include name="errorLogger" />
    </aop:aspectj-autoproxy>

    <bean id="errorLogger" class="org.springframework.webflow.samples.util.ErrorLogger" />
</beans>

ErrorLogger has the following

@Aspect
public class ErrorLogger implements Serializable {

    @Pointcut("execution(* org.springframework.webflow.samples.util.SearchCriteria.*(..))")
    public void say(){}

    @Before("say()")
    public void sayHi(){
        System.out.println("sayHi()");
    }
}

org.springframework.webflow.samples.util.SearchCri teria has method

public void throwExcept(){
        System.out.println("throwExcept()");
        try{
            //int error = 2/0;
            System.out.println("Annie are u OK?");
        }
        catch(Exception e){
           System.out.println("throwExcept()"+e.getMessage());
           e.printStackTrace();
          //throw new Exception(e);
        }
     }

to trigger the aspect in the flow...

<var name="searchCriteria" class="org.springframework.webflow.samples.util.SearchCriteria" />

        <on-start>
            <evaluate expression="searchCriteria.throwExcept()" />
        </on-start>

when this runs I get

2009-11-28 17:14:38,031 DEBUG [org.springframework.webflow.execution.AnnotatedAction] - <Putting action execution attributes map[[empty]]>
throwExcept()
Annie are u OK?

so the aspect doesn't get triggered.

However if I change the pointcut to..

@Before("execution(public * *(..))")

the aspect does get triggered and I get "sayHi" everywhere
eventually crashing the API.

So what gives? why doesn't

@Pointcut("execution(* org.springframework.webflow.samples.util.SearchCriteria.*(..))")

This work? I've tried many variations but no way of selecting my method ( as a test run).

Is Webflow complicating the way Spring AOP normally works?

[Marten Deinum]

You say use AspectJ because it uses compile-time weaving...

I'm trying @AspectJ with java 5 annot. and
just trying to get it working.

First of all you aren't using loadtime or compile time weaving, you are still using spring aop, which is proxy based.

Next each flow xml results in a BeanFactory/ApplicationContext itself. Spring AOP only works on beans defined in the same applicationcontext. Spring AOP (when it kicks in) doesn't know about your SearchCriteria bean and will never know about your SearchCriteria bean because it is local to the flow and not the applicationcontext the aop stuff is defined in.

[jokrasa]

Hi Marten,

Thanks for your help and interest in this matter!

OK so I tried Load-Time Weaving (LTW) as you advised ...

I placed the aop.xml where my persistence.xml resides ( I'm hoping this gets recognized because of the errors I get)

<!DOCTYPE aspectj PUBLIC
        "-//AspectJ//DTD//EN" "http://www.eclipse.org/aspectj/dtd/aspectj.dtd">
<aspectj>
    <weaver>
        <!-- only weave classes in this package will include subpkgs -->
        <include within="org.springframework.webflow.samples..*"/>
    </weaver>
    <aspects>
        <!-- use only this aspect for weaving -->
        <!-- <aspect name="org.springbyexample.aspectjLoadTimeWeaving.PerformanceAdvice" /> -->
        <aspect name="org.springframework.webflow.samples.util.ErrorLogger" />
    </aspects>
</aspectj>

In my main config I am trying to find what to put as weaver class?

<context:load-time-weaver  aspectj-weaving="on"  weaver-class="???"  />

If nothing then ..

java.io.NotSerializableException: org.springframework.context.weaving.DefaultContextLoadTimeWeaver

If I place the class (from spring-agent.jar) in the server and set the javaagent ../libs/Spring-agent.jar in the
catalina.bat of Tomcat so that it starts

if not exist "%CATALINA_BASE%\conf\logging.properties" goto noJuli
set JAVA_OPTS=%JAVA_OPTS% -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.util.logging.config.file="%CATALINA_BASE%\conf\logging.properties -javaagent:../server/lib/spring-agent.jar"

then it too is not serialized. So I then added "implements Serialization" to the class jar it put it in play,
and get..

java.io.NotSerializableException: org.apache.catalina.loader.WebappClassLoader

and so on with no hope of serializing the chain of implyed classes
( for this reason I feel I am on the wrong track...)

Must I write some kind of Custom LoadTimeWeaving class and how could you do this?
I saw the following config at http://www.springbyexample.org/examp...pectj-ltw.html
but was unable to see/checkout the sc

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
                        http://www.springframework.org/schema/beans/spring-beans.xsd
                        http://www.springframework.org/schema/context 
                        http://www.springframework.org/schema/context/spring-context.xsd">

    <context:load-time-weaver />
    
    <bean id="processor" class="org.springbyexample.aspectjLoadTimeWeaving.Processor" />
    
</beans>

In short, just how does one config and implement aspectj (LTW) for Webflow??
I don't see anything out there really, is it possible?
Webflow requires serialization for snapshots etc,...

I just know there's something I'm missing/overlooked!

Can anyone stear/help me in the right direction?

There's just nothing on AOP for webflow in the manual or forums!



Hope to hear from someone,

Best Regards,

John.

[cbawad]

Hi John,

I used the documentation at following link and got it working smoothly.

http://static.springsource.org/sprin...#aop-ataspectj
Look the example in section

8.8.4 Load-time weaving with AspectJ in the Spring Framework

Cheers.
Deepak