Spring AOP vs AspectJ

Spring AOP is simpler than using AspectJ as there is no requirement to introduce the compiler into build processes for Compile Time Weaving. If you only need to advise the execution of operations on Spring beans, then Spring AOP is the right choice. If you need to advise objects not created by the Spring container, then you will need to use AspectJ. You will also need to use AspectJ if you wish to advise join points other than simple method executions (for example, field get or set join points, and so on).When using AspectJ, you have the choice of the AspectJ language syntax or the @AspectJ annotation style. Clearly, if you are not using Java 5+ then the choice has been made for you… use the code style. If aspects play a large role in your design, and you are able to use the AspectJ Development Tools (AJDT) plugin for Eclipse, then the AspectJ language syntax is the preferred option: it is cleaner and simpler because the language was purposefully designed for writing aspects. If you are not using Eclipse, or have only a few aspects that do not play a major role in your application, then you may want to consider using the @AspectJ style and sticking with a regular Java compilation in your IDE, and adding an aspect weaving phase to your build script.

Moreover following are the conclusive differences in Spring AOP and AspectJ.
Spring-AOP : Runtime weaving through proxy using concept of dynamic proxy if interface exists or cglib library if direct implementation provided.
AspectJ: Compile time weaving through AspectJ Java Tools(ajc compiler) if source available or post compilation weaving (using compiled files).Also, load time weaving with Spring can be enabled – it needs the aspectj definition file and offers flexibility. Compile time weaving can offer benefits of performance (in some cases) and also the joinpoint definition in Spring -aop is restricted to method definition only which is not the case for AspectJ.