如何防止Spring Boot AOP删除类型注释？

Question

我对Spring Boot及其AOP的风格还很陌生，但对于使用其他语言和AOP框架进行编程却并不陌生。我不确定如何解决这一挑战。

我有一个简单的元数据装饰器：

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface GreetingsMeta {
    public float version() default 0;
    public String name() default "";
}

通过依赖项注入就可以正常工作：

public GreetingController(List<IGreetingService> greetings) throws Exception {
    this.greetings = new HashMap<>();
    greetings.forEach(m -> {
        Class<?> clazz = m.getClass();
        if (clazz.isAnnotationPresent(GreetingsMeta.class)) {
            GreetingsMeta[] s = clazz.getAnnotationsByType(GreetingsMeta.class);
            this.greetings.put(s[0].name(), m);
        }
    });
}

直到我应用了标准的日志记录方面：

@Aspect
@Component
public class LoggingAspect {
    @Around("execution(* com.firm..*(..)))")
    public Object profileAllMethods(ProceedingJoinPoint joinPoint) throws Throwable {
        MethodSignature methodSignature = (MethodSignature) joinPoint.getSignature();
        String methodName = methodSignature.getName();
        final StopWatch stopWatch = new StopWatch();
        stopWatch.start();
        Object result = joinPoint.proceed();
        stopWatch.stop();
        LogManager.getLogger(methodSignature.getDeclaringType())
        .info(methodName + " " + (stopWatch.getTotalTimeSeconds() * 1000) + " µs");
        return result;
    }
}

然后注释数据列表变为空，即使@Component注释也消失了。

示例元修饰类：

@Component
@GreetingsMeta(name = "Default", version = 1.0f)
public class DefaultGreetingsService implements IGreetingService {


    @Override
    public String message(String content) {
        return "Hello, " + content;
    }
} 

我应该如何排除故障？

Answer 1

您可能想调查AnnotationUtils

Method method = methodSignature.getMethod();
GreetingsMeta greetingsMeta = AnnotationUtils.findAnnotation(method, GreetingsMeta.class);