Creating our own aspects using custom annotations

Question

I am new to Annotations and new to StackOverflow and this is my first question. I am trying to write custom annotations which will help me trace and log method executions.

For example:

class A
{

@Logthis

void methodA();

}

Here whenever the method methodA() is executed, I want to log to a file telling "we are entering the methodA in class A" and when methodA is over "we are exiting methodA in class A" something like this. We vil have a number of classes and methods.

I know that this can be done using AspectJ. I have done it by defining pointcuts and joinpoints. But I want to do it using custom annotations.

It will be very helpful if anyone can guide me as to how to go about this.

Thanks in advance.

Answer 1

Using AspectJ you do the following :-

Create an Aspect Class annotated with @Aspect

Annotation a method in the class with @Around and define the value to be execution on classes that you have annotated. You will also need to have enabled proxying of you classes by AspectJ.

@Aspect
public class LoggerAspect {

    @Around(value = "execution(@you.custom.Annotation * *(..))")
    public Object logMethod(ProceedingJoinPoint joinPoint) throws Throwable
    {
        // DO LOGGING HERE
    }

}

Answer 2

You can use Log4J. Here is a tutorial of it:

http://javakane.blogspot.fr/2012/07/automate-log4j-logging-with-aop-and.html