Aspect-oriented approaches have recently had a tremendous impact on the characterization of crosscutting concerns during the development of software systems. However, issues in transforming early aspects in the design stage into final codes still remain to be addressed. In this paper, we focused on operator conversion rules, which convert the early aspects described in state diagrams into AspectJ codes systematically. By weaving these aspect codes into base codes, a final system can be obtained that is enhanced by early aspects in a systematic manner. A tool that supports the conversion rules of the operators was developed. The tool transforms the aspect behaviors described in the aspect-enhanced state diagram into aspect code. To validate our proposed method, a meeting scheduler system was designed and implemented.