Introduction to Spring - Spring Enterprise Recipes: A Problem Solution Approach - page 48

How It Works

Before Advices
To create a before advice to handle crosscutting concerns before particular program execution points,
you use the @Before annotation and include the pointcut expression as the annotation value.

package com.apress.springenterpriserecipes.calculator;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
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() {
log.info("The method add() begins");
}
}

This pointcut expression matches the add() method execution of the ArithmeticCalculator
interface. The preceding wildcard in this expression matches any modifier ( public , protected , and
private ) and any return type. The two dots in the argument list match any number of arguments.
To register this aspect, you just declare a bean instance of it in the IoC container. The aspect bean
may even be anonymous if there's no reference from other beans.

<beans ...>
...
<bean class="com.apress.springenterpriserecipes.calculator.

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CalculatorLoggingAspect" />
</beans>

You can test your aspect with the following Main class:

package com.apress.springenterpriserecipes.calculator;

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");