I'm writing custom aspect handles annotation for method invocation time measurement. I'm not sure that no one will implement his custom aspect for the same annotation. But I want to be sure that my aspect will be the last in annotation handling order for the most accurate time measurement.
If I put two aspects in context with @Order specification by my own
@Component
@Order(HIGHEST_PRECEDENCE)
@Aspect
public class Aspect1{}
@Component
@Order(LOWEST_PRECEDENCE)
@Aspect
public class Aspect2{}
it works well.
But if I specify @Order only above Aspect2, the order breaks. I can't be sure that any who wan't to handle the same annotation will implement Ordered interface or specify @Order annotation.
There're certain rules about AOP handling in spring. If you don't implement the Ordered interface or don't have Order annotation imply you don't care about the order and such aspects are put at the end of ordered aspects.
For example
Class1 has implemented Ordered with order 10
Class2 has Order annotation with value 2
Class3 and Class4 neither have Order annotation nor they implement Ordered interfaces. In this case, Class3 and Class 4 can be in any order.
For this example, if all Aspects satisfy the execution criteria then they will be called as Class1 <- Class2 <- Class3 <- Class4 or Class1 <- Class2 <- Class4 <- Class3
So if you really want your annotation should be at the last, then you should not implement the Ordered interface and should not have Order annotation. But as said this can be problematic as well if other Aspect also satisfies the same execution criteria and they also have neither Order annotation nor that have implemented Ordered annotation.