AOP 通过aspectj实现引入通知

aspectj是Spring提供的可以通过代码的注释自动生成XML配置的包，这样可以简化代码使配置文件变得更为简单，但也无法机动的修改XML文件了，而且由于将代理的配置交给了aspectj处理，所以也无法看到SpringAOP代理的配置信息。但对于提高开发效率还是很有价值的。

如下两个接口：

TargetInterface是原始的对象接口而AdviceInterface是我们需要引入的借口。DefTarget和DefAdvice是上两个接口的实现。

1. packageaspectTest;
3. publicinterfaceTargetInterface{
4. publicvoidfunctionA();
5. publicintfunctionB();
6. }

1. packageaspectTest;
3. publicinterfaceAdviceInterface{
4. publicvoidfunctionC();
5. publicintfunctionD();
6. }

1. packageaspectTest;
3. publicclassDefTargetimplementsTargetInterface{
5. publicvoidfunctionA(){
6. System.out.println("functionA...");
7. }
9. publicintfunctionB(){
10. System.out.println("functionB...");
11. return0;
12. }
14. }

1. packageaspectTest;
3. publicclassDefTargetimplementsTargetInterface{
5. publicvoidfunctionA(){
6. System.out.println("functionA...");
7. }
9. publicintfunctionB(){
10. System.out.println("functionB...");
11. return0;
12. }
14. }

TargetAspect是Aspect实现代理的注释类，Aspect会访问其中的注释去配置AOP代理

1. packageaspectTest;
3. importorg.aspectj.lang.annotation.Aspect;
4. importorg.aspectj.lang.annotation.DeclareParents;
5. importorg.aspectj.lang.annotation.Pointcut;
6. importaop.CallTracker;
7. importaop.DefaultCallTracker;
10. @Aspect
11. publicclassTargetAspect{
12. //方法名无所谓，Aspect之会寻找注释名
13. //定义切入点
14. @Pointcut("execution(*aspectTest.*.*(..))")
15. privatevoidsetterServiceCall(){}
17. //定义需要实现的对象（接口）
18. @DeclareParents(
19. value="aspectTest.*",
20. defaultImpl=DefAdvice.class)//接口的实现类
21. publicstaticAdviceInterfacemixin;
22. }

Spring的配置文件，比较简单了

1. <?xmlversion="1.0"encoding="UTF-8"?>
2. <beansxmlns="http://www.springframework.org/schema/beans"
3. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4. xmlns:aop="http://www.springframework.org/schema/aop"
5. xsi:schemaLocation="
6. http://www.springframework.org/schema/beans
7. http://www.springframework.org/schema/beans/spring-beans.xsd
8. http://www.springframework.org/schema/aop
9. http://www.springframework.org/schema/aop/spring-aop.xsd">
10. <beanid="target"class="aspectTest.DefTarget"/>
11. <beanclass="aspectTest.TargetAspect"/>
12. <aop:aspectj-autoproxy/>
14. </beans>

Main:

1. packageaspectTest;
4. importorg.springframework.context.ApplicationContext;
5. importorg.springframework.context.support.ClassPathXmlApplicationContext;
7. importservices.StockService;
8. importservices.UserService;
10. importjava.math.BigDecimal;
11. importjava.util.Date;
13. publicclassMain{
15. publicstaticvoidmain(String[]args){
16. ApplicationContextac=newClassPathXmlApplicationContext(
17. "aspectTest/context.xml"
18. );
19. TargetInterfaceti=(TargetInterface)ac.getBean("target");
20. ti.functionA();
21. ti.functionB();
22. describeTracker(ti);
23. }
24. privatestaticvoiddescribeTracker(Objecto){
25. AdviceInterfacet=(AdviceInterface)o;
26. t.functionC();
27. t.functionD();
28. }
30. }