Cleanest way of validating AWS credentials with aws-java-sdk

During the application startup, I want to check if my AWS credentials are valid before I try to run any other AWS request (such as SNS, SQS and S3 requests).

What's the cleanest way of doing this?

Even the simplest operations such as getting the list of my own policies requires having the policy iam:ListPolicies, is there a very simple request that doesn't require any policies at all?