This aspect demonstrates how to implement logging of method and constructor entry/exit. This is something I created recently for a client to replace more than 10,000 lines of logging code.

LoggingAspect.aj

package com.piazzaconsulting.aspect;

import org.apache.log4j.Logger;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.reflect.MemberSignature;

public aspect LoggingAspect {
   private static final String POINTCUT = 
      "execution(* com.yourcompany.whatever..*(..)) || initialization(com.yourcompany.whatever..new(..))";

   @Before(POINTCUT)
   public void logEntryAdvice(JoinPoint joinPoint) {
      MemberSignature signature = (MemberSignature)joinPoint.getSignature();
      Logger logger = Logger.getLogger(signature.getDeclaringTypeName());
      logger.trace(">>> " + signature.getName());
   }

   @After(POINTCUT)
   public void logExitAdvice(JoinPoint joinPoint) {
      MemberSignature signature = (MemberSignature)joinPoint.getSignature();
      Logger logger = Logger.getLogger(signature.getDeclaringTypeName());
      logger.trace("<<< " + signature.getName());
   }
}