private void setEndpoint(DefaultRequest<Void> signableRequest, GetIamAuthTokenRequest request) {
        try {
            // Add the protocol to make the signer happy
            signableRequest.setEndpoint(new URI(String.format("http://%s:%d", request.getHostname(), request.getPort())));
        } catch (URISyntaxException e) {
            throw new AmazonClientException("Invalid endpoint provided", e);
        }
    }
Create an authorization token used to connect to a database that uses RDS IAM authentication.
aws-java-sdk-rds/src/main/java/com/amazonaws/services/rds/auth/RdsIamAuthTokenGenerator.java