参考书籍《spring in action》
1. AOP
before you wak the walk, you have to learn to walk the walk.
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
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
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‘)
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.
