Preview:
@Aspect
public class ThrowOnNullFirstArgAspect {
    @Pointcut("" +
            "within(@org.springframework.stereotype.Controller *) || " +
            "within(@(@org.springframework.stereotype.Controller *) *)")
    private void isController() {}

    @Around("isController()")
    public Object executeAroundController(ProceedingJoinPoint point) throws Throwable {
        throwIfNullFirstArgIsPassed(point);
        return point.proceed();
    }

    private void throwIfNullFirstArgIsPassed(ProceedingJoinPoint point) {
        if (!(point.getSignature() instanceof MethodSignature)) {
            return;
        }

        if (point.getArgs().length > 0 && point.getArgs()[0] == null) {
            throw new IllegalStateException("The first argument is not allowed to be null");
        }
    }
}
downloadDownload PNG downloadDownload JPEG downloadDownload SVG

Tip: You can change the style, width & colours of the snippet with the inspect tool before clicking Download!

Click to optimize width for Twitter