SpringBootApiGatewayRequestHandler - AWS HTTP GET method support

[ghost]

When using SpringBootApiGatewayRequestHandler with AWS - HTTP GET method throws exception "Cannot convert event".

This line fails as request body is null.
Object body = deserializeBody(event.getBody());

	protected Object convertEvent(APIGatewayProxyRequestEvent event) {
		Object body = deserializeBody(event.getBody());
		if (functionAcceptsMessage()) {
			return new GenericMessage<>(body, getHeaders(event));
		}
		else {
			return body;
		}
	}

[olegz]

So, you're saying that because of GET you don't have a body. If so what would we use to create Publisher.
Anyway, can you elaborate a bit on what you're trying to do . . .some code etc.

[artembilan]

The queryParams map can be used as a default palyoad.
This is what we do in Spring Integration for the WebFluxInboundEndpoint:

return extractRequestBody(exchange)
		.doOnSubscribe(s -> this.activeCount.incrementAndGet())
		.switchIfEmpty(Mono.just(exchange.getRequest().getQueryParams()))
		.map(body -> new HttpEntity<>(body, exchange.getRequest().getHeaders()))
		.flatMap(entity -> buildMessage(entity, exchange))

Just an idea to consider...

[olegz]

Thanks @artembilan , and yes indeed we need to do something there, yet I am still waiting for @iwejay to communicate what was he trying to accomplish.

[ghost]

Thank you @olegz and @artembilan
Sorry about the late response and not providing enough details.

I am learning AWS Lambda used along with serverless framework.
I was trying this sample code to expose REST API from AWS Lambda using AWS API Gateway.
https://github.com/iwejay/aws-java-spring-cloud-function-demo

MemberFunctionApplication contains 3 function beans exposed as endpoints over HTTP GET (serverless.yml).

'officers' and 'members' functions are same thing - just tried Publisher and Function with void input.
Both of these methods fails when i do HTTP GET. Below is the log from CloudWatch - which indicates error in body parsing.

Cannot convert event: java.lang.IllegalStateException
	java.lang.IllegalStateException: Cannot convert event
	at org.springframework.cloud.function.adapter.aws.SpringBootApiGatewayRequestHandler.deserializeBody(SpringBootApiGatewayRequestHandler.java:54)
	at org.springframework.cloud.function.adapter.aws.SpringBootApiGatewayRequestHandler.convertEvent(SpringBootApiGatewayRequestHandler.java:36)
	at org.springframework.cloud.function.adapter.aws.SpringBootApiGatewayRequestHandler.convertEvent(SpringBootApiGatewayRequestHandler.java:17)
	at org.springframework.cloud.function.adapter.aws.SpringBootRequestHandler.handleRequest(SpringBootRequestHandler.java:47)
	Caused by: java.lang.NullPointerException
	at com.fasterxml.jackson.core.JsonFactory.createParser(JsonFactory.java:889)
	at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3004)
	at org.springframework.cloud.function.adapter.aws.SpringBootApiGatewayRequestHandler.deserializeBody(SpringBootApiGatewayRequestHandler.java:51)

Thanks to @artembilan again, got it working as per his suggestion, i tried a simple version of passing the query param to Lambda. Please see AwsApiGatewayGetRequestHandler and MemberFunctionApplication's member method.

Kindly guide and let me know if any further details required.

[ghost]

Link to original article about Spring Cloud Functions + AWS + Serverless

[pfrank13]

I've hit the same issue and looked at the upcoming 2.0.0.M3 which appears to have the same bug. Using API Gateway with HTTP GET which results in a null body and ends up with a NPE when trying to be deserialized. I believe @iwejay has provided enough info but I can too if needed, also thanks to @artembilan as well as @iwejay because that workaround worked for me too.

[olegz]

Given the age of this issue and the amount of new features and improvements that went into AWS adapter I am going to close this issue, but please feel free to raise a new one based on our current support.