日常开发中经常会使用到 Spring AOP，通知类型有：
Around、Before、After、AfterReturning、AfterThrowing，本文主要讲解五种通知都有时，正常和异常情况下的执行顺序，以及多个切面存在时，执行顺序如何
正常逻辑代码
- 接口定义如下
public interface UserService {
void saveUser();
void deleteUser();
}
- 接口实现代码如下
@Slf4j
@Component
public class UserServiceImpl implements UserService {
@Override
public void saveUser() {
log.info("save user");
}
@Override
public void deleteUser() {
log.info("delete user");
System.out.println(1 / 0);
}
}
针对正常接口 UserService 定义两个切面逻辑
- 切面一
@Slf4j
@Order(99)// 注意顺序
@Aspect
@Component
public class UserServiceAspect {
@Before("execution(* com.lushwe.aspect.service.impl..*(..))")
public void before() {
log.info("before");
}
@Around("execution(* com.lushwe.aspect.service.impl..*(..))")
public Object around(ProceedingJoinPoint proceedingJoinPoint) throws Throwable {
log.info("around开始");
Object proceed = proceedingJoinPoint.proceed();
log.info("around结束");
return proceed;
}
@After("execution(* com.lushwe.aspect.service.impl..*(..))")
public void after() {
log.info("after");
}
@AfterReturning("execution(* com.lushwe.aspect.service.impl..*(..))")
public void afterReturning() {
log.info("afterReturning");
}
@AfterThrowing("execution(* com.lushwe.aspect.service.impl..*(..))")
public void afterThrowing() {
log.info("afterThrowing");
}
}
- 切面二
@Slf4j
@Order(100)// 注意顺序
@Aspect
@Component
public class UserServiceAspectTwo {
@Before("execution(* com.lushwe.aspect.service.impl..*(..))")
public void before() {
log.info("before");
}
@Around("execution(* com.lushwe.aspect.service.impl..*(..))")
public Object around(ProceedingJoinPoint proceedingJoinPoint) throws Throwable {
log.info("around开始");
Object proceed = proceedingJoinPoint.proceed();
log.info("around结束");
return proceed;
}
@After("execution(* com.lushwe.aspect.service.impl..*(..))")
public void after() {
log.info("after");
}
@AfterReturning("execution(* com.lushwe.aspect.service.impl..*(..))")
public void afterReturning() {
log.info("afterReturning");
}
@AfterThrowing("execution(* com.lushwe.aspect.service.impl..*(..))")
public void afterThrowing() {
log.info("afterThrowing");
}
}
正常情况下执行顺序，打印日志如下
2020-04-17 15:27:55.500 INFO 4329 --- [ main] com.lushwe.aspect.UserServiceAspect : around开始
2020-04-17 15:27:55.501 INFO 4329 --- [ main] com.lushwe.aspect.UserServiceAspect : before
2020-04-17 15:27:55.501 INFO 4329 --- [ main] com.lushwe.aspect.UserServiceAspectTwo : around开始
2020-04-17 15:27:55.501 INFO 4329 --- [ main] com.lushwe.aspect.UserServiceAspectTwo : before
2020-04-17 15:27:55.501 INFO 4329 --- [ main] c.l.aspect.service.impl.UserServiceImpl : save user
2020-04-17 15:27:55.503 INFO 4329 --- [ main] com.lushwe.aspect.UserServiceAspectTwo : around结束
2020-04-17 15:27:55.503 INFO 4329 --- [ main] com.lushwe.aspect.UserServiceAspectTwo : after
2020-04-17 15:27:55.503 INFO 4329 --- [ main] com.lushwe.aspect.UserServiceAspectTwo : afterReturning
2020-04-17 15:27:55.503 INFO 4329 --- [ main] com.lushwe.aspect.UserServiceAspect : around结束
2020-04-17 15:27:55.503 INFO 4329 --- [ main] com.lushwe.aspect.UserServiceAspect : after
2020-04-17 15:27:55.503 INFO 4329 --- [ main] com.lushwe.aspect.UserServiceAspect : afterReturning
有异常情况下执行顺序，打印日志如下
2020-04-17 15:20:55.403 INFO 4227 --- [ main] com.lushwe.aspect.UserServiceAspect : around开始
2020-04-17 15:20:55.403 INFO 4227 --- [ main] com.lushwe.aspect.UserServiceAspect : before
2020-04-17 15:20:55.403 INFO 4227 --- [ main] com.lushwe.aspect.UserServiceAspectTwo : around开始
2020-04-17 15:20:55.403 INFO 4227 --- [ main] com.lushwe.aspect.UserServiceAspectTwo : before
2020-04-17 15:20:55.403 INFO 4227 --- [ main] c.l.aspect.service.impl.UserServiceImpl : delete user
2020-04-17 15:20:55.403 INFO 4227 --- [ main] com.lushwe.aspect.UserServiceAspectTwo : after
2020-04-17 15:20:55.405 INFO 4227 --- [ main] com.lushwe.aspect.UserServiceAspectTwo : afterThrowing
2020-04-17 15:20:55.405 INFO 4227 --- [ main] com.lushwe.aspect.UserServiceAspect : after
2020-04-17 15:20:55.406 INFO 4227 --- [ main] com.lushwe.aspect.UserServiceAspect : afterThrowing
Exception in thread "main" java.lang.ArithmeticException: / by zero
...（详细异常信息省略）...
总结
- 正常情况下执行顺序：
Aroundstart ->Before->Aroundend ->After->AfterReturning - 有异常情况下执行顺序：
Aroundstart ->Before->After->AfterThrowing，有异常时，Aroundend 逻辑不会执行 - 当有多有切面时，按照
@Order顺序依次执行，从上面日志可以看出
- 本文完，希望对你有帮助
