Do annotations also couples code with framework like spring?

Extending spring based interfaces is discouraged as it unnecessarily couples the code with Spring. Does the same reasoning applies to annotations as well? We need to have them imported in the source co开发者_高级运维de before using them.

I'll take the opposite viewpoint--of course using a Spring-specific annotation ties the class to Spring. I claim it's self-evident that importing and using Spring annotations ties the code to Spring (although you could trivially redefine those annotations for a non-Spring environment). The key for me is how deeply it's tied to Spring.

It's easier to check for, and process, annotations, than it is to restructure a class hierarchy or duplicate the functionality of a non-marker interface. Assuming you wanted to leave the annotations in, and could duplicate the logic behind the annotations, it'll be easier to do that (IMO) than to recreate whatever class/interface hierarchy implemented similar functionality.

The other key is the word "unnecessarily". I have yet to create a Spring application and need those classes outside of a Spring environment. When I have (generally for exposed APIs) it's been at the interface level. Note, however, that I knew from the onset that this exposure would exist and I planned accordingly.

Most would argue that this does not. While you've imported those annotations needed to ensure that Spring handles the request or wraps the transactions, you are not extending or implementing a specific class or interface.

Think about it this way, when you've annotated that class you're telling Spring to do various things based upon your configuration. Take out those annotations, and what you have is a POJO which just has some methods. It's a completely valid object without those annotations, it might not do what you wish it do (i.e. handle requests), but the code is still performing the same logic as it was with the annotations -- you are just now responsible for calling it appropriately.