如何找到带有特定注释的所有Java对象（而非类）？

Question

I am designing a system to update member variables in objects automatically by marking them with some annotation. Some other background thread will then update the objects.

To do this, the runtime component doing the updating needs to know all Java objects that contain this annotation. I can see that there are methods to find classes with an annotation type, but going from classes to instances of the classes is a lot harder. I want to avoid explicitly "registering" the object in the constructor, although I could do that as a last resort.

Any suggestions as to how this might be achieved?

Answer 1

You can use some kind of HashMap cache to store objects for update.

1) write annotation @Updatable to mark objects updatable

2) write HashMap that will contain all the objects to update

3) initialize this HashMap on time of app initialization by lookup the objects with @Updatable If you are using Spring that you can write custom BeanPostProcessor for that purposes.