在编译时执行java注释

Question

Hi : I wanted to make sure that an annotation is present at compile time in a class. Is this possible ? I realize that annoataions are, themselves, classes, so I assume so - but Im just not sure syntactically where and how to enforce/implement such a structure in my classes.

Answer 1

You can write an annotation processor to run arbitrary logic at compile time.

From an annotation processor, you can do things like check whether a class has a particular structure or member present if a particular annotation exists on that class. They are pretty flexible - for more of an idea of what you can do with them check out the API . They are also supported in major IDEs such as Eclipse and Netbeans.

An introduction to writing an annotation processor is here .