在方面中读取注释属性

Question

如何读取方面中的注释属性值？

我希望对所有使用@Transactional注释的关节点执行我的Around建议(readonly = false).

@Around("execution(* com.mycompany.services.*.*(..)) "
+ "&& @annotation(org.springframework.transaction.annotation.Transactional)")
public Object myMethod(ProceedingJoinPoint pjp) throws Throwable {
}

Answer 1

你可以不用手动处理签名,这种方式(argNames用于在没有调试信息的情况下编译时保留参数名称):

@Around(
    value = "execution(* com.mycompany.services.*.*(..)) && @annotation(tx)",
    argNames = "tx") 
public Object myMethod(ProceedingJoinPoint pjp, Transactional tx) 
    throws Throwable {
    ...
} 

见7.2.4.6建议参数

Answer 2

你可以这样做：

注解：

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Profiled {
    public boolean showArguments();
}

拦截器：

@Aspect
public class ProfilingAspect {

    public static Logger log = LoggerFactory.getLogger("ProfilingAspect");

    @Around("@annotation(profiled)")
    public Object profiled(final ProceedingJoinPoint pjp,
            final Profiled profiled) throws Throwable {
        StopWatch sw = new StopWatch();
        try {
            sw.start();
            return pjp.proceed();
        } finally {
            sw.stop();
            StringBuilder sb = new StringBuilder();
            sb.append("Method ");
            sb.append(pjp.getSignature().getName());
            if (profiled.showArguments()) {
                sb.append(" with arguments ");
                sb.append(Arrays.toString(pjp.getArgs()));
            }
            sb.append(" took ");
            sb.append(sw.getTime());
            sb.append(" millis");
            log.info(sb.toString());
        }
    }
}