Unable to integrate API gateway with aws lambda - amazon-web-services

Question

I am trying to integrate AWS API Gateway with an AWS lambda function. The integration works flawlessly until I use the 'Lambda Proxy integration' in my Integration Request.
When I check 'Use Lambda Proxy integration' in my integration request, I start getting:
"Execution failed due to configuration error: Malformed Lambda proxy
response"
I googled around a bit and realized that I need to send back the response in a certain format:
{
"isBase64Encoded": true|false,
"statusCode": httpStatusCode,
"headers": { "headerName": "headerValue", ... },
"body": "..."
}
However, despite doing that, I still continue to see the same error. What am I doing wrong?
This is what my Lambda function looks like:
#Override
public String handleRequest(Object input, Context context) {
context.getLogger().log("Input: " + input);
return uploadN10KWebsiteRepositoryToS3();
}
private String uploadN10KWebsiteRepositoryToS3() {
/*BitbucketToS3Upload.JsonResponse jsonResponse = new BitbucketToS3Upload.JsonResponse();
jsonResponse.body = "n10k_website repository uploaded to S3...";
String jsonString = null;
try {
ObjectMapper mapper = new ObjectMapper();
jsonString = mapper.writeValueAsString(jsonResponse);
HashMap<String, Object> test = new HashMap<String, Object>();
test.put("statusCode", 200);
test.put("headers", null);
test.put("body", "n10k_website repository uploaded to S3");
test.put("isBase64Encoded", false);
jsonString = mapper.writeValueAsString(test);
}
catch (Exception e) {
int i = 0;
}*/
//return jsonString;
return "{\"isBase64Encoded\":false, \"statusCode\":200, \"headers\":null, \"body\": \"n10k_website repository uploaded to S3\"}";
}
When I test the API from API Gateway console, this is the response I get:
Received response. Integration latency: 4337 ms Mon Aug 07 00:33:45
UTC 2017 : Endpoint response body before transformations:
"{\"isBase64Encoded\":false, \"statusCode\":200, \"headers\":null,
\"body\": \"n10k_website repository uploaded to S3\"}"
Mon Aug 07 00:33:45 UTC 2017 : Endpoint response headers:
{x-amzn-Remapped-Content-Length=0,
x-amzn-RequestId=0ff74e9d-7b08-11e7-9234-a1a04edc223f,
Connection=keep-alive, Content-Length=121, Date=Mon, 07 Aug 2017
00:33:45 GMT,
X-Amzn-Trace-Id=root=1-5987b565-7a66a2fd5fe7a5ee14c22633;sampled=0,
Content-Type=application/json}
Mon Aug 07 00:33:45 UTC 2017 : Execution failed due to configuration
error: Malformed Lambda proxy response
Mon Aug 07 00:33:45 UTC 2017 : Method completed with status: 502
If I un-check the 'Use Lambda Proxy integration', everything works okay. But I want to know why my response is malformed and how to fix it. Thanks!

Answer 1

I figured it out. I was sending the response back in an incorrect manner.
The response had to be sent back as a POJO object directly rather than serializing the POJO and sending it back as a String. This is how I got it to work.
public class BitbucketToS3Upload implements RequestHandler<Object, JsonResponse> {
#Data
public static class JsonResponse {
boolean isBase64Encoded = false;
int statusCode = HttpStatus.SC_OK;
String headers = null;
String body = null;
}
#Override
public JsonResponse handleRequest(Object input, Context context) {
context.getLogger().log("Input: " + input);
return uploadN10KWebsiteRepositoryToS3();
}
private JsonResponse uploadN10KWebsiteRepositoryToS3() {
BitbucketToS3Upload.JsonResponse jsonResponse = new BitbucketToS3Upload.JsonResponse();
jsonResponse.body = "n10k_website repository uploaded to S3";
String jsonString = null;
try {
ObjectMapper mapper = new ObjectMapper();
jsonString = mapper.writeValueAsString(jsonResponse);
System.out.println(jsonString);
//jsonString = mapper.writeValueAsString(test);
}
catch (Exception e) {
int i = 0;
}
return jsonResponse;
//return "{\"isBase64Encoded\":false, \"statusCode\":200, \"headers\":null, \"body\": \"n10k_website repository uploaded to S3\"}";
}
}
Hope this helps someone!