[findFirstAnnotatedArgument] #java #springboot #@aspect

findFirstAnnotatedArgument.java

@Aspect
public class ControllerJsonStyleAdvice {
	private Object findFirstAnnotatedArgument(JoinPoint joinPoint, Class annotation) {
        Object[] args = joinPoint.getArgs();
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        Method method = signature.getMethod();

        Annotation[][] parameterAnnotations = method.getParameterAnnotations();

        for (int i = 0; i < parameterAnnotations.length; i++) {
            for (int j = 0; j < parameterAnnotations[i].length; j++) {
                if (annotation.isAssignableFrom(parameterAnnotations[i][j].getClass())) {
                    return args[i];
                }
            }
        }
        return null;
    }
    
    @Before(value = "commonPointcut()")
    public void setupParams(JoinPoint joinPoint) throws Throwable {
		Object requestBodyArgument = findFirstAnnotatedParameter(joinPoint, RequestBody.class);
        /* ... */
    }
    
}