This question is a follow up to a question I found before  

[java: get all variable names in a class](https://stackoverflow.com/questions/2126714/java-get-all-variable-names-in-a-class)

What I want is to get variables from a class, but instead of getting them all, I want only the variables that have the annotation `@isSearchable` .

So basically I have 2 questions : 

* How do I create an annotation ?
* How to filter my fields by only this annotation ?

And one more thing , if it is something I'm using frequently is it advisable (I'm guessing reflections should be slow).

Thank you