AOP Not working with Spring 3 MVC application

[Anoop Nair]

Hi All,

I have a Spring 3.0 MVC application that works fine. I want to introduce AOP in this application. However on doing this I am getting the below exception.

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.web.servlet.mvc.
annotation.DefaultAnnotationHandlerMapping#0': Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: 
Error creating bean with name 'org.springframework.web.servlet.handler.MappedInterceptor#0': Initialization of bean failed; nested exception is 
org.springframework.aop.framework.AopConfigException: Could not generate CGLIB subclass of class 
[class org.springframework.web.servlet.handler.MappedInterceptor]: Common causes of this problem include using a final class or a non-visible class; nested exception is java.lang.IllegalArgumentException: Cannot subclass final class class org.springframework.web.servlet.handler.MappedInterceptor

Below is the application code:

Controller

package com.myapp.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

import com.myapp.service.IMyService;

@Controller
public class MyController {

	@Autowired
	private IMyService service;
	
	@RequestMapping(value = "/")
	public String myAction(Model model) {
		service.showMessage();
		return "home";
	}
}

Model interface and implementation:

package com.myapp.service;

public interface IMyService {
	public void showMessage();
}

----------------------------------
package com.myapp.service;

import org.springframework.stereotype.Component;

@Component
public class MyServiceImpl implements IMyService {

	@Override
	public void showMessage() {
		System.out.println("in impl... hello world");	
	}
}

package com.myapp.aspects;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;

@Component
@Aspect
public class MyAspect {

	@Pointcut("execution(* com.myapp.service.*.*(..))")
        public void myPointCut() { }
	
	@Before("myPointCut()")
	public void profile(JoinPoint jp) throws Throwable {
                System.out.println("Going to call the method... "+jp.getSignature().getName()); 
	}
}

<?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:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd"> <context:component-scan base-package="com.myapp"/> <mvc:annotation-driven/> <context:annotation-config/> <aop:aspectj-autoproxy /> </beans>


Can someone please point out what I am doing wrong with this ??

[Mark Spritzler]

It looks like it is trying to make a Proxy out of a Core Spring MVC object. Why, I am not sure.

But typically in MVC applications, you create two different ApplicationContexts. One for just the web layer components, and one for the middle tier. Your Service and AOP should be in the middle tier. Create a file called applicationContext.xml put it in your WEB-INF directory. Do the component-scan and aop autoproxy in that file. Add in your web.xml the xml for adding the Spring ContextLoaderListener. This will create the middle tier application context.

For your DispatcherServlet, create an xml file called <<<XXX>>>-servlet.xml where the <<<XXX>>> is replaced with the servlet name you give your DispatcherServlet entry in your web.xml. Place this file also in the WEB-INF directory and only include your web layer beans. and <mvc:annotation-driven/>

Also in your middle tier xml you don't need both <context:annotation-config/> and <context:component-scan.../> component-scan includes all the beans you get with annotation-config. So by putting in annotation-config, you are just adding redundancy

[Anoop Nair]

Thanks Mark.

That works perfectly now.

Although, I still do not understand why it was throwing an exception when the aop config was present in the same file.

[Mark Spritzler]

Anoop Nair wrote:Thanks Mark.

That works perfectly now.

Although, I still do not understand why it was throwing an exception when the aop config was present in the same file.

This just exposed your Web Layer beans to the AOP process and AOP decided it wanted to create a proxy and around a Spring MVC core class.

Mark