How to process an SNS message in AWS Lambda written in Java?

Thanks to the comments by @dnault and @notionquest I found that this object is part of the aws-lambda-java-events library. I added the dependency:

compile 'com.amazonaws:aws-lambda-java-events:1.3.0'

And now I can do:

public class ArchiveRequestHandler implements RequestHandler<SNSEvent, Void> {

    @Override public Void handleRequest(SNSEvent input, Context context) {
        // do something with the message
        return null;
    }
}

The following Lambda code processes the SNS input message/s:

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.LambdaLogger;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.amazonaws.services.lambda.runtime.events.SNSEvent;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;

public class LogEvent implements RequestHandler<SNSEvent, Object> {

    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd_HH:mm:ss");

    public Object handleRequest(SNSEvent request, Context context){

        String timeStamp = sdf.format(new Date());
        LambdaLogger logger = context.getLogger();

        logger.log("-------------------------Invocation started: --------------" + timeStamp);
        List<SNSEvent.SNSRecord> snsRecordList = request.getRecords();
        if ( snsRecordList != null ){
            SNSEvent.SNS recordSNS = null;
            for ( SNSEvent.SNSRecord snsRecord : snsRecordList ) {
                recordSNS = snsRecord.getSNS();
                logger.log(
                     "Subject:[" + recordSNS.getSubject() + "]" +
                            "Arn:[" + recordSNS.getTopicArn() + "]" +
                             "attribs:[" + recordSNS.getMessageAttributes() + "]" +
                             "message:[" + recordSNS.getMessage() + "]" );
            }//for
        }

        timeStamp = sdf.format(new Date());
        logger.log("-------------------------Invocation completed: -------------" + timeStamp);
        return null;
    }
}