[aspectj-users] Per-control-flow aspect question

["Pavel Kusch" <paul@xxxxxxxxxxxxxx>]

Hello,

 

I have been using AspectJ for 3 days now and it is great. I would like to introduce it to our project immediatelly. Please could anybody verify my design since I am new to this cool stuff.

 

I would like to use AspectJ for managing logging, exception handling, singletons and .....

 

We are developing middleware application that gets correlation id from client for logging. We need different instance of the logger for each transaction. Entry point for the application is a stateless session bean that delegates to POJO Facade (singleton). I thought to use Per-control-flow aspect which would be instantiated when any of the Facade methods are called. Then there would be one aspect holding the logger per thread available for the whole execution. Each concurrent transaction executing in different thread would have its own logger. Please see below the aspect code.

 

Questions:

1) Are my assumtions about Per-control-flow aspect correct? Or should it be done in different way?

2) Do I need to specify cflow() in the facadeExceptions() pointcut?

 

Thank you,

 

Pavel

 

******************************************** ASPECT *****************************************************************

package aspekty;

 

import org.aspectj.lang.*;

 

public aspect LoggerAspect percflow (expCall()){
 Logger logger;
 
 pointcut expCall() : target(Facade) &&
                      (call(public void executeFirst(int))  ||
                       call(public void executeSecond(int)) ||
                       call(public void executeThird(int)));
 
 before (int par): expCall() && args(par){
     Container container = new Container();
     LoggerFactory factory = container.getLoggerFactory();
     logger = factory.getLogger(par);
 }
 
//Log exception and let it go to ExceptionHandlerAspect to process
 pointcut facadeExceptions(): call(public void Facade.*(..)) ||
                              call(private void ServiceAccess.disconnect());
               
 after() throwing(Throwable ex): facadeExceptions() {
     logger.log(ex);
 }
 

 

//Log entry to facade methods
    pointcut facadeEntry(Facade facade): target(facade) &&
                                         execution (public void *(..));
   
    before(Facade facade): facadeEntry(facade) {
  Signature sig = thisJoinPointStaticPart.getSignature();
  String context = "[" + sig.getDeclaringType().getName() + "." + sig.getName() + "]";
  logger.logEntry(context);
    }
}