spring学习--4
参考书籍《spring in action》
1. AOP
before you wak the walk, you have to learn to walk the walk.
![](https://images2015.cnblogs.com/blog/745114/201604/745114-20160404104212453-1920918515.png)
1) advice---the job of an aspect (what and when)
/before
/after
/after-returning
/after throwing
/around: beforen and after
2) join points---a point in the execution of the application where an aspect can be plugged in.
3)pointcuts---where the advice should be woven
![](https://images2015.cnblogs.com/blog/745114/201604/745114-20160404111137250-290004067.png)
4)aspects--- advice & joincuts
5)introduction---add new methods or attributes to existing classes.
6)weaving---the process of applyng aspects to target object to create a
new proxied object.
/compile time
/class load time
/runtime
2. spring 对AOP的支持方式
1)classic spring proxy-based AOP
![](https://images2015.cnblogs.com/blog/745114/201604/745114-20160404105813422-1093178398.png)
2)pure-POJO aspects
3) @AspectJ annotation driven aspects.
4) injected AspectJ aspects.
3.creating aspect in spring
1)selecting join points with pointcuts.
eg:
execution(* concert.Performance.perform())
and bean('woodstock')
and bean('woodstock')
![](https://images2015.cnblogs.com/blog/745114/201604/745114-20160404110553156-1042627580.png)
2) creating annotated aspects
@Aspect public class Audience { @Pointcut("execution(** concert.Performance.perform(..))") public void performance() {} @Before("performance()") public void silenceCellPhones() { System.out.println("Silencing cell phones"); } @Before("performance()") public void takeSeats() { System.out.println("Taking seats"); } @AfterReturning("performance()") public void applause() { System.out.println("CLAP CLAP CLAP!!!"); } @AfterThrowing("performance()") public void demandRefund() { System.out.println("Demanding a refund"); } }
配置:
@Configuration @EnableAspectJAutoProxy @ComponentScan public class ConcertConfig { @Bean public Audience audience() { return new Audience(); } }
3)handling params in advice
4) annotation introductions
dynamic language like ruby and groovy can add new methods to an object or class.
To follow the path:
look to the master,
follow the master,
walk with the master,
see through the master,
become the master.