Pointer for Simple demo log AOP program

[sumanta]

Dear All,
Can you please give a pointer or url where i will get a simple demo log
related AOP program?

Thanks in advance.

Regards,
Sumanta

[jamestastic]

Step 1) Create your logger.

package com.earldouglas.aoplogging;

import org.apache.log4j.Logger;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;
import org.springframework.util.StopWatch;

@Component
@Aspect
public class MethodLogger {

	@Around("execution(* com.earldouglas..*.*(..))")
	public Object timeMethod(ProceedingJoinPoint joinPoint) throws Throwable {
		StopWatch stopWatch = new StopWatch();
		stopWatch.start();

		Object retVal = joinPoint.proceed();

		stopWatch.stop();

		StringBuffer logMessageStringBuffer = new StringBuffer();
		logMessageStringBuffer.append(joinPoint.getTarget().getClass().getName());
		logMessageStringBuffer.append(".");
		logMessageStringBuffer.append(joinPoint.getSignature().getName());
		logMessageStringBuffer.append("(");
		logMessageStringBuffer.append(joinPoint.getArgs());
		logMessageStringBuffer.append(")");
		logMessageStringBuffer.append(" execution time: ");
		logMessageStringBuffer.append(stopWatch.getTotalTimeMillis());
		logMessageStringBuffer.append(" ms");

		Logger.getLogger(this.getClass()).info(logMessageStringBuffer.toString());

		return retVal;
	}

}

Step 2) Set up your context.

<?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"
	xmlns:context="http://www.springframework.org/schema/context"
	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
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd">

	<aop:aspectj-autoproxy />
	
	<context:component-scan base-package="com.earldouglas.aoplogging" />

	<bean class="com.earldouglas.greeter.DefaultGreeter" />

</beans>

Now any beans in com.earldouglas.* will have the @Around-annotated advice wired in to log their execution time.

In my example, I have an interface Greeter, with an implementation DefaultGreeter.

[jamestastic]

I have written a short example which should provide a bit more detail.