How AspectJ is used: An analysis of eleven Aspectj programs

Abstract. While it is well-known that crosscutting concerns occur in many software projects, little is known on how aspect-oriented program-ming and in particular AspectJ have been used. In this paper, we ana-lyze eleven AspectJ programs by different authors to answer the ques-tions: which mechanisms are used, to what extent, and for what purpose. We found the code of these programs to be on average 86 % object-oriented, 12 % basic AspectJ mechanisms (introductions and method ex-tensions), and 2 % advanced AspectJ mechanisms (homogeneous advice or advanced dynamic advice). There is one class of crosscutting concerns – which is mostly concerned with introductions and method extensions – that matches this result well: collaborations. These results and our discussions with program authors indicate the bulk of coding activities was implementing collaborations. Several studies and researchers suggest that languages explicitly supporting collaborations are better suited than aspects a ̀ la AspectJ for this task.