设置用于调用Lambda函数的有效负载

Question

I am trying to invoke a Lambda function from another Lambda function in Java. I am following the code provided in this Question "How to call an aws java lambda function from another AWS Java Lambda function when both are in same account, same region" .

Refer to this statement in the code:

invokeRequest.setPayload(ipInput);

Where I am guessing the ipInput variable is a String.

What I need to know is how should I set a payload, that is not String? In my case, the Lambda function accepts a List<Double> input. From what I read, it seems I need to convert it to a JSON String. I am sceptical about how? Is there a difference between the JSON representation of Double[] and List<Double> ? Also, is there any helper method in AWS SDK (or the Collections API), which can do that cleanly?

Answer 1

There is a post on the AWS Devloper blog regarding this topic.

You could implement a proxy.

Otherwise you could check the AWS SDK directly on github or go to the official java-doc there seem to be two options for your payload either you pass a ByteBuffer or a String . It seems like you cannot pass a Double or a Double[] directly. You have to wrap those in a JSON-String. I'm receiving JSON messages containing numbers and it works quite well. Try something like:

String myDoubles = "{\"doubles\": [1487851012.924, 1487851012.925]}"
invokeRequest.setPayload(myDoubles);