Getting started with ASPECTJ

Many software developers are attracted to the idea of AOP, but unsure about how to begin using the technology. They recognize the concept of crosscutting concerns, and know that they have had problems with the implementation of such concerns in the past. But there are many questions about how to adopt AOP into the development process. Common questions include: Can I use aspects in my existing code? What kinds of benefits can I expect to get? How do I find aspects? How steep is the learning curve for AOP? What are the risks of using this new technology?