How to invoke AWS Lambda functiuon which handles APIGatewayProxyRequestEvent?

Question

I have an AWS Lambda function, implemented in Java, which is behind APIGateway. It works fine with:

.
.
.
public APIGatewayProxyResponseEvent handleRequest(APIGatewayProxyRequestEvent input, Context context) 
.
.
.

I want to invoke the function from a Java app with:

.
.
APIGatewayProxyRequestEvent event = new APIGatewayProxyRequestEvent();
// tried to use almost all setters
InvokeRequest req = new InvokeRequest()
       .withFunctionName("<Lambda arn>")
       .withPayload(event.toString());
// here, I also tried many options

The Lambda is invoked, but checking thru CloudWatch, I see nothing as an input APIGatewayProxyRequestEvent. And, with various event setters I experience something like:

om.amazonaws.services.lambda.model.InvalidRequestContentException: Could not parse request body into json: Could not parse payload into json: Unexpected character ('r' (code 114)): was expecting double-quote to start field name
 at [Source: (byte[]); line: 1, column: 3] (Service: AWSLambda; Status Code: 400; Error Code: InvalidRequestContentException; Request ID: ..........

How can I specify that the invoked lambda function expects APIGatewayProxyRequestEven as an input argument? I've got a feeling that I miss something very simple, but can not find it. Thanks.

Answer 1

You've created your Lambda function to be invoked by Amazon API Gateway. In your code example it looks like you're trying to invoke the function directly.

Instead make a suitable http call to the API Gateway endpoint url.