Spring AOP with mvc

[juniad Ahmed]

Hi,
I have implemented simple Spring AOP example but i have no idea how to implement AOP with MVC, Can any one give me an example of Spring MVC with AOP or link to the site which has this example.

Thanks in advance

[Mark Spritzler]

What do you mean by Spring AOP with MVC?

Spring AOP can advise any Spring Bean. So if you want to advice a class you have as a Spring Bean, you just define your Pointcut expression to match those classes and methods. Then when your ApplicationContext gets created Spring automatically creates Proxies for those classes. There isn't anything special you need to do with Spring MVC to add AOP that you wouldn't do with any Spring application.

Mark

[juniad Ahmed]

I applied the advice to the bean but still advice classes doing their job.

package manchester.united.DAO;

/**
 *
 * @author juahmed
 */
public interface Adder {
     public int add(int a,int b);


}



package manchester.united.DAO;

/**
 *
 * @author juahmed
 */
public class AdderImpl implements Adder {
    public int add(int a, int b){
        return a+b;
    }


}



/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package manchester.united.action;

/**
 *
 * @author juahmed
 */

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import manchester.united.DAO.Adder;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.AbstractController;
public class AddController extends AbstractController {

    Adder adder;

    public Adder getAdder() {
        return adder;
    }

    public void setAdder(Adder adder) {
        this.adder = adder;
    }

     protected ModelAndView handleRequestInternal(HttpServletRequest request, HttpServletResponse response)throws Exception
        {

        String one=  request.getParameter("one");
         String two=  request.getParameter("two");
            System.out.println("adder==="+one+two);
            int c=adder.add(1, 45);
            System.out.println("dao==="+c);
            return new ModelAndView("success");
        }

}





package manchester.united.advice;

/**
 *
 * @author juahmed
 */
import java.lang.reflect.Method;
import org.springframework.aop.AfterReturningAdvice;

public class LogAfterReturningAdvice implements AfterReturningAdvice{

    public void afterReturning(Object returnValue, Method method, Object[] args,
    Object target) throws Throwable {

        System.out.println("After Normal Return from Method");
    }

}


package manchester.united.advice;

/**
 *
 * @author juahmed
 */
import java.lang.reflect.Method;
import org.springframework.aop.MethodBeforeAdvice;

public class LogBeforeCallAdvice implements MethodBeforeAdvice{

    public void before(Method method, Object[] args, Object target) {
        System.out.println("Before Calling the Method");
    }

}


<?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:p="http://www.springframework.org/schema/p"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">

    <bean class="org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping"/>
    
    <!--
    Most controllers will use the ControllerClassNameHandlerMapping above, but
    for the index controller we are using ParameterizableViewController, so we must
    define an explicit mapping for it.
    -->
    <bean id="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
        <property name="mappings">
            <props>
                <prop key="index.htm">indexController</prop>
                 <prop key="addAction.htm">addController</prop>
            </props>
        </property>
    </bean>
    
    <bean id="viewResolver"
          class="org.springframework.web.servlet.view.InternalResourceViewResolver"
          p:prefix="/WEB-INF/jsp/"
          p:suffix=".jsp" />
    
    <!--
    The index controller.
    -->
    <bean name="indexController"
          class="org.springframework.web.servlet.mvc.ParameterizableViewController"
          p:viewName="index" />

     <bean name="addController" class="manchester.united.action.AddController">
        <property name="adder" ref="myAdderImpl" />
    </bean>

    <bean id="myAdderImpl" class="manchester.united.DAO.AdderImpl"></bean>

    <bean id = "beforeCall"
    class = "manchester.united.advice.LogBeforeCallAdvice" />

    <bean id = "afterCall"
    class = "manchester.united.advice.LogAfterReturningAdvice" />


    <bean id = "adder"
    class = "org.springframework.aop.framework.ProxyFactoryBean">

        <property name = "proxyInterfaces">
            <value>manchester.united.DAO.Adder</value>
        </property>

        <property name = "interceptorNames">
            <list>
                <value>beforeCall</value>
                <value>afterCall</value>
                <value>throwCall</value>
                <value>aroundCall</value>
            </list>
        </property>

        <property name = "target">
            <ref bean = "myAdderImpl"/>
        </property>
    </bean>


</beans>

program executes successfully and i get the success page. but i dont see the advice classes printing their messages on console
Please help

[Mark Spritzler]

I don't see your PointCut Expression.

What I do see is a format for Spring that is very old, while using the latest Spring jars.

If you are learning Spring, I recommend using the latest versions of Spring and not use any old tutorials or documentation.

Like, i don't implement or extend any Spring class or interface in any of my classes. I keep them 100% POJO. I do like using Annotations, but you don't have to.

For AOP you can use xml to define your pointcut expressions.

Checkout the Spring documentation of Spring AOP. Here is the link for the xml way to do it. I highly recommend doing it this way as it is much simpler.
http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/aop.html#aop-schema

Mark

[juniad Ahmed]

Hi Mark,

I tried to implement what you said but was unsuccessful. mark it will be really nice for me or any new Spring programmer if you can give a sample program with comments.

Thanks

[juniad Ahmed]

Hi Mark,
I got the example working.
Here is the code which is working fine. If you feel some think can be improved please comment.

package com.apress.springrecipes.calculator;

/**
 *
 * @author juahmed
 */
public interface ArithmeticCalculator {

    public double add(double a, double b);
    public double sub(double a, double b);
    public double mul(double a, double b);
    public double div(double a, double b);

}




package com.apress.springrecipes.calculator;

/**
 *
 * @author juahmed
 */
public class ArithmeticCalculatorImpl implements ArithmeticCalculator {
    public double add(double a, double b) {
        double result = a + b;
        System.out.println(a + " + " + b + " = " + result);
        return result;
    }
    public double sub(double a, double b) {
        double result = a - b;
        System.out.println(a + " - " + b + " = " + result);
        return result;
    }
    public double mul(double a, double b) {
        double result = a * b;
        System.out.println(a + " * " + b + " = " + result);
        return result;
    }
    public double div(double a, double b) {
        if (b == 0) {
        throw new IllegalArgumentException("Division by zero");
        }
        double result = a / b;
        System.out.println(a + " / " + b + " = " + result);
        return result;
        }
}





package com.apress.springrecipes.calculator;

/**
 *
 * @author juahmed
 */
public interface UnitCalculator {
    public double kilogramToPound(double kilogram);
    public double kilometerToMile(double kilometer);

}



package com.apress.springrecipes.calculator;

/**
 *
 * @author juahmed
 */
public class UnitCalculatorImpl implements UnitCalculator {
    public double kilogramToPound(double kilogram) {
        double pound = kilogram * 2.2;
        System.out.println(kilogram + " kilogram = " + pound + " pound");
        return pound;
    }
    public double kilometerToMile(double kilometer) {
        double mile = kilometer * 0.62;
        System.out.println(kilometer + " kilometer = " + mile + " mile");
        return mile;
    }
}


package com.apress.springrecipes.calculator;

/**
 *
 * @author juahmed
 */

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
@Aspect
public class CalculatorLoggingAspect {
//private Log log = LogFactory.getLog(this.getClass());



@Before("execution(* ArithmeticCalculator.add(..))")
public void logBefore(JoinPoint joinPoint) {
    System.out.println("method name===="+joinPoint.getSignature().getName());
    System.out.println("before call");
}
}



package com.apress.springrecipes.calculator;

/**
 *
 * @author juahmed
 */
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Main {
public static void main(String[] args) {
    ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
    ArithmeticCalculator arithmeticCalculator =
    (ArithmeticCalculator) context.getBean("arithmeticCalculator");
    arithmeticCalculator.add(1, 2);
    arithmeticCalculator.sub(4, 3);
    arithmeticCalculator.mul(2, 3);
    arithmeticCalculator.div(4, 2);
    UnitCalculator unitCalculator =
    (UnitCalculator) context.getBean("unitCalculator");
    unitCalculator.kilogramToPound(10);
    unitCalculator.kilometerToMile(5);
    }
}




<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-3.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
    
<!--To enable AspectJ annotation support -->
<aop:aspectj-autoproxy />

<bean class="com.apress.springrecipes.calculator.CalculatorLoggingAspect" />
<bean id="arithmeticCalculator"
class="com.apress.springrecipes.calculator.ArithmeticCalculatorImpl" />
<bean id="unitCalculator"
class="com.apress.springrecipes.calculator.UnitCalculatorImpl" />
</beans>

[Mark Spritzler]

Yeah, that looks nice. You are now using the Annotations and now your classes are truly pojos. Which means you can write simple unit tests for all the classes including the Aspect class. But you will have to stub/mock out a JoinPoint object. There is a way to have Spring go into the JoinPoint directly for you. Examples of that are in the Spring Documentation under the AOP section.

Good Luck

Mark