Output the input of a lambda when triggered?

I have a very simple piece of lambda code (written in java), and the trigger is based on a "PUT" in an S3 bucket. It listens directly to the bucket via the Lambda trigger dashboard.

There are two questions here, that might help me get my input logged by the lambda :

1 ) Since this is a trigger pointed directly at S3 from the lambda dashboard, show the first argument of my lambda be something OTHER than an SNSEvent? Is this a different type of event? If so, what am I looking for - because I need this to be directly triggered in the way I have this configured.

2 ) Once I have the right object in that signature, do I simple LOG.info the object to see it in monitoring? or do I need to do some other magic

EDIT : Since I mentioned the signature - here is right now :

public static void lambdaMethod(SNSEvent input, Context context) throws IOException { 

I am not sure if that first argument is correct, for a direct trigger.