java - AspectJ MethodSignature 为 getParameterNames() 返回 null

Question

我有一个方面根据目标方法的细节进行各种计算，因此预先提取这些内容如下:

    @Around("execution(* com.xyz.service.AccountService.*(..))")
public void validateParams(ProceedingJoinPoint joinPoint) throws Throwable {
    final MethodSignature signature = (MethodSignature) joinPoint.getSignature();

    final String methodName = signature.getName();
    final String[] parameterNames = signature.getParameterNames();
    final Object[] arguments = joinPoint.getArgs();
    ...
    ...
    ...
    joinPoint.proceed();
}

在提取的详细信息中，除了始终返回 null 的 parameterNames 之外，所有信息都反射(reflect)了预期的信息。我希望它按照下面的签名返回 {accountDetails}。谁知道我可能遗漏了什么，或者这是一个错误？

这是我正在处理的目标方法的签名:

Long createAccount(RequestAccountDetails accountDetails);

Answer 1

对我有用:

@Aspect
public class MyAspect {

    @Around("execution(* *(..)) && !within(MyAspect)")
    public Object validateParams(ProceedingJoinPoint joinPoint) throws Throwable {
        final MethodSignature signature = (MethodSignature) joinPoint.getSignature();

        final String[] parameterNames = signature.getParameterNames();
        for (String string : parameterNames) {
            System.out.println("paramName: " + string);
        }

        return joinPoint.proceed();

    }
}

输出:paramName: accountDetails

我已将 validateParams 的签名更改为:public Object validateParams(ProceedingJoinPoint joinPoint) throws Throwable 因为 createAccount() 返回一个 Long。否则我会得到错误:applying to join point that doesn't return void: {0}