Learn Java for Web Development

220 CHAPTER 5: Building Java Web Applications with Spring Web MVC

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19. <aop:pointcut id = "log"


20. expression="execution( .getAllBooks())" />


21. <aop:before pointcut-ref = "log"


22. method="logBefore" />


23. <aop:after pointcut-ref = "log"


24. method="logAfter" />


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   Lines 9 to 10: You use Spring’s aop configuration namespace to declare that the

LoggingAspect bean is an aspect.

   Line 15: You declare the LoggingAspect as a bean. Even if the Spring Framework

transforms a POJO to an aspect by declaring it as an aspect in the context, it

still has to be declared as a Spring <bean>.

   Line 18: Then you refer to that bean in the <aop:aspect> element.

   Lines 19 to 20: The pointcut is defined in the preceding <pointcut> element with

an expression attribute set to select where the advice should be applied. The

expression syntax is AspectJ’s pointcut expression language.

   Lines 21 to 22: You declare (using <aop:before>) that before the getAllBooks()

method is executed, the LoggingAspect’s logBefore method should be called.

This is called before advice. The pointcut-ref attribute refers to a pointcut

named log.

   Lines 23 to 24: You (using <aop:after>) declare that the logAfter method should

be called after getAllBooks() has executed. This is known as after advice. The

pointcut-ref attribute refers to a pointcut named log.

Listing 5-22 illustrates the stand-alone Java application.

Listing 5-22. Stand-Alone Java Application

1. package com.apress.aop;


2. import org.springframework.context.ApplicationContext;


3. import org.springframework.context.support.ClassPathXmlApplicationContext;


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5. public class Driver {


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7. public static void main(String...args){


8. ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");


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