Reusable Lambda for Multiple Event Types (Java)

Question

I want to write an AWS Lambda function that is able to respond to various types of event types: API Gateway, Kinesis, S3, etc. 
The API/SDK I need to work with is Java. 
I'd like to create a general-purpose handler, but it appears that each service has its own event type and does not derive from some common parent event type. 
Is there a pattern or a best practice for creating an AWS Lambda function that can be used with a variety of event types? Or do I need to create a custom handler for each event type?

Answer

Hi Brian,

One approach is to try to find a common “parent” to all those event types. As everything is an object in Java, you could argue that your handler could accept Object type as the event.

The drawback is that then you ll have to cast and use instanceof operator, not ideal but it will work.

Another approach is to use Map and/or Inputstream as shown here: https://docs.aws.amazon.com/lambda/latest/dg/java-handler.html.

Hope it helps

Reusable Lambda for Multiple Event Types (Java)

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