Passing and using properties through annotations in Java

Question

I have a Java EE Application in which I have an Interceptor class like this

@Interceptor
@Logged
public class LogInterceptor {

@AroundInvoke
    public Object logMethod(InvocationContext context) throws Exception {
      ...
    }
}

Now when I want it to work I annotate the target method with @Logged. Please correct me if my perception of this is wrong.

Now to the question.

Is it possible to pass/bind a variable (and when, how?) throught the annotation like so:

@Logged(ctx = methodContext)
public void someMethod(MethodContext methodContext) {
   ...
}

and then a use it in LogInterceptor.logMethod() ?

Or are there other options to accomplish this?

It seems to me that you are confusing aspect-oriented programming (code-injection (just prior to runtime)) with dependency injection (data/field @runtime). From your question -- I am going to assume that you are looking for a (more) flexible mechanism to configure your logger -- so separate the configuration from the implementation The solution would be for you to dependency-inject the context (@Autowired ???) into your aop class (your logger)... An alternative would be for your aop-class (again -- your logger) to retrieve the context from a JNDI lookup or from a bean — Greg Patnude
– Greg Patnude, Commented Jul 11, 2019 at 17:09

Michał Kosmulski · Accepted Answer · 2019-07-11 12:47:11Z

2

The values of annotation parameters must be compile-time constants, so you cannot "pass a variable" this way. But how should this even work? Where would methodContext be defined and who would be responsible for setting the value? You are, however, free to pass compile-time constants, so for example:

@Logged(loggerName = "MY_LOGGER")
public void ...

is completely fine.

answered Jul 11, 2019 at 12:47

Michał Kosmulski

3,60221 silver badges20 bronze badges

Add a comment |

Stack Exchange Network

Passing and using properties through annotations in Java

1 Answer 1

Hot Network Questions

Passing and using properties through annotations in Java

1 Answer 1

Related

Hot Network Questions