What Is Spring AOP?
While AOP isn't often discussed, it is used extensively in Spring. Maybe it's about time you got familiar with AOP and how to make it work for you.
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What do you know about Spring AOP? Do you use it in your current Spring Boot projects? If not, this is for you!
Nowadays, I see a lot of projects using all the latest technologies made in Spring Boot and other cutting-edge frameworks. On one hand, it sounds promising, but on the other hand, I often see that developers are not taking full advantage of the technologies in front of them.
I think it is primarily because a majority of books and documentation are too academic and difficult to understand. That is why I decided to talk a bit about aspect-oriented programming.
What Is Aspect Oriented Programming (AOP)?
Aspect-oriented programming is a programming paradigm that tries to solve problems with cross-cutting concerns. Aspect-oriented programming (AOP) complements object-oriented programming (OOP) by providing a different way to think about program structure.
The key unit of modularity in OOP is the class; whereas in AOP, the unit of modularity is the aspect.
In a more simpler word, it helps us to refactor the different necessary repeating codes into different modules. This gives us the benefit that we can maintain these functionalities in one single place, instead of it writing down every time.
This approach will result in a much more maintainable code, which clears the business logic from the most confusion factor. We separate these functionalities along different aspects.
An aspect is a modularization of a concern that cuts across multiple classes. Unified logging or transaction management can be a good example of it.
Simplify Code Using AOP
Let us see the given code example below.
Here, you can recognize a couple of different concerns, which are not related to the business logic itself. We should separate these into another place. Henceforward, only the business logic has left.
How AOP Works on a Large Scale
If you have a system that contains several packages and classes that you do not use with AOP, such as tracing, transactions, and exception handling, we have to implement them in every class and every method.
This results in two problems:
- Code tangling: — Each class and method contains tracing, transactions, and exception handling — even business logic. In a tangled code, it is often hard to see what is actually going on in a method.
- Code scattering — Aspects such as transactions are scattered throughout the code and not implemented in a single specific part of the system.
Using AOP allows you to solve these problems. So, what AOP does is it takes all the transaction code and puts it into a transaction aspect. Then, it takes all the tracing code and puts that into an aspect. Finally, exception handling is put into an aspect.
Afterward, there will be a clean separation between the business logic and all additional aspects.
An important concept in AOP is cross-cutting concerns. Above, I show a few examples of tracing, exception handling, and transactions, which are all cross-cutting concerns. Several classes and methods must implement them.
In classic object-oriented programing, they cannot implement in a single place, so you will not be able to avoid scattering and code tangling.
Aspect-oriented programming allows you to implement cross-cutting concerns in one centralized place. So, if you use AOP, the way it works is that you implement your business logic first, then you ride aspects for your cross-cutting concerns.
That way, you can compose your infrastructure and choose whether you would like to add transactions or logging to your code. Therefore, you can create your own individual customized middleware. Then, you use Spring AOP to add the aspects to your application so that, at runtime, the aspects, as well as your main line business logic, is actually executed.
What Is Spring AOP?
If you check out my article about the Spring framework, you can see that it is one of the core building modules for Spring.
It supports aspect-oriented modularization in our projects by eliminating code tangling and cross-cutting concerns. Adding the Spring AOP library to our project, you can start to get the advantages of several different tools that it contains.
This could be for tools such as annotations, advice, joinpoints, and pointcuts. These are the most essential foundations of the library.
Usually, you use AOP to implement enterprise features that make the Spring framework more useful.
AOP allows you to define exactly where you would like to integrate the specific aspects that you defined. Hence, you will get a configurable middleware. If you would like to know more about Spring AOP, stay tuned for upcoming articles or visit this site.
In this article, I attempted to clarify the concept of aspect-oriented programming and introduce you to how it relates to the Spring framework. In my upcoming articles, I will go deeper into Spring AOP library, what are the main cornerstones of it, and how you can use it Hope I could help! Let us know what you think in the comments below and don't forget to share!
Published at DZone with permission of Zoltan Raffai, DZone MVB. See the original article here.
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