AWS DynamoDB trigger using Lambda in JAVA

Question

I am trying to trigger an AWS lambda function written in Java, on dynamodb stream events. Amazon has a guide for the same, using NodeJS here http://docs.aws.amazon.com/lambd

Answer 1

This worked for me - case DynamoDB stream events:

import com.amazonaws.services.lambda.runtime.RequestHandler;
...

public class DynamoStreamHandler implements RequestHandler {
    @Override
    public Void handleRequest(Object o, Context context) {

        LinkedHashMap lhm = (LinkedHashMap) o;
        ...etc.
    }
}

It seems they use a customized JSON mapper which utilizes Map and List objects. It's quite straightforward (but tedious) to verify this for other event types by testing and print-outing logs. (sigh)

EDIT: If ~5 MB overhead is ok, you can use DynamodbEvent.DynamodbStreamRecord provided by aws-lambda-java-events library v1.1.0 as described in AWS Lambda Walkthrough 3: Process Amazon DynamoDB Events (Java) in AWS Lambda Documentation.