Spring AOP 之多切面

article/2025/8/18 19:36:01

接着上文：https://blog.csdn.net/single_wolf_wolf/article/details/81772837

多切面相对来说，只是定义多个切面类，同时配置类中设置一下，

demo如下：

首先定义一个接口：

package com.cmb.multi;public interface MultiAsp {public void test();
}

再给出实现：

package com.cmb.multi;import org.springframework.stereotype.Component;@Component
public class MultiAspImpl implements MultiAsp {public void test() {System.out.println("This is a test for multi aspect!");}}

不要忘记@Component

其中test()是连接点

切面一：

package com.cmb.multi;import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;@Aspect
public class Aspect1 {@Pointcut("execution(* com.cmb.multi.MultiAspImpl.test(..))")public void print(){}@Before("print()")public void before(){System.out.println("before 1 ....");}@After("print()")public void after(){System.out.println("after 1 ....");}@AfterReturning("print()")public void afterReturning(){System.out.println("afterReturning 1 ....");}@AfterThrowing("print()")public void afterThrowing(){System.out.println("afterThrowing 1 ....");}}

切面二：

package com.cmb.multi;import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;@Aspect
public class Aspect2 {@Pointcut("execution(* com.cmb.multi.MultiAspImpl.test(..))")public void print(){}@Before("print()")public void before(){System.out.println("before 2 ....");}@After("print()")public void after(){System.out.println("after 2 ....");}@AfterReturning("print()")public void afterReturning(){System.out.println("afterReturning 2 ....");}@AfterThrowing("print()")public void afterThrowing(){System.out.println("afterThrowing 2 ....");}
}

切面三：

package com.cmb.multi;import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;@Aspect
public class Aspect3 {@Pointcut("execution(* com.cmb.multi.MultiAspImpl.test(..))")public void print(){}@Before("print()")public void before(){System.out.println("before 3 ....");}@After("print()")public void after(){System.out.println("after 3 ....");}@AfterReturning("print()")public void afterReturning(){System.out.println("afterReturning 3 ....");}@AfterThrowing("print()")public void afterThrowing(){System.out.println("afterThrowing 3 ....");}
}

然后给出配置类：MultiConfig

package com.cmb.multi;import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;@Configuration
@EnableAspectJAutoProxy
@ComponentScan("com.cmb.multi")
public class MultiConfig {@Beanpublic Aspect1 getAspect1(){return new Aspect1();}@Beanpublic Aspect2 getAspect2(){return new Aspect2();}@Beanpublic Aspect3 getAspect3(){return new Aspect3();}
}

最后我们测试一下:主函数：

package com.cmb.multi;import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;public class MultiMain {public static void main(String[] args) {//使用AnnotationConfigApplicationContext 加载配置文件ApplicationContext ctx = new AnnotationConfigApplicationContext(MultiConfig.class);MultiAsp multiAsp = ctx.getBean(MultiAsp.class);multiAsp.test();}}

结果如下：

before 1 ....
before 2 ....
before 3 ....
This is a test for multi aspect!
after 3 ....
afterReturning 3 ....
after 2 ....
afterReturning 2 ....
after 1 ....
afterReturning 1 ....

结果很尴尬，和书本上不一致，书上说目前这种写法的话，多个切面是无序的，结果应该是

before 1 ....
before 3 ....
before 2 ....
This is a test for multi aspect!
after 2 ....
afterReturning 2 ....
after 3 ....
afterReturning 3 ....
after 1 ....
afterReturning 1 ....

但是，笔者不信邪，连续运行了十几次，结果还是第一种，目前猜测是我的框架比较新，不知道是不是框架内部默认了顺序，探后我修改MultiConfig配置类如下：

@Beanpublic Aspect3 getAspect3(){return new Aspect3();}@Beanpublic Aspect1 getAspect1(){return new Aspect1();}@Beanpublic Aspect2 getAspect2(){return new Aspect2();}

对，就是把Aspect3放到了最上面的位置，然后查看结果如下：

before 3 ....
before 1 ....
before 2 ....
This is a test for multi aspect!
after 2 ....
afterReturning 2 ....
after 1 ....
afterReturning 1 ....
after 3 ....
afterReturning 3 ....

结果居然变换了，目前看来，Spring AOP框架中关于多个切面的执行顺序是按照配置类中Bean的注入来的。

然后我们使用@Order 把切面分别修改为：

@Aspect
@Order(3)@Aspect
@Order(1)@Aspect
@Order(2)

同时配置类中Bean顺序还是3， 1 ，2

运行主函数，结果如下：

before 1 ....
before 2 ....
before 3 ....
This is a test for multi aspect!
after 3 ....
afterReturning 3 ....
after 2 ....
afterReturning 2 ....
after 1 ....
afterReturning 1 ....

看到没！！！运行顺序被掰过来，对吧，这个就是@Order的功劳，这里就是使用这个注解规定多切面的执行顺序，最后给出一张图，SPringAOP的多代理情况下，，使用的是责任链模式：