import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.LambdaLogger;
import java.util.HashMap;
import java.util.Map;
public class LambdaAPIGateway {
public Map<String, Object> handleRequest(Map<String, Object> request, Context context) {
LambdaLogger logger = context.getLogger();
logger.log("Function version: " + context.getFunctionVersion() + "; ");
logger.log("Event: " + request.toString());
String bodyAsJson = "{\"data\":\"ok\"}";
Map<String, Object> result = Respond(200, bodyAsJson, context);
return result;
}
public static Map<String, Object> Respond(int httpStatus, String bodyAsJson, Context context) {
Map<String, Object> retval = new HashMap<>();
/**
Response MUST be in a specific format with "headers"; "statusCode" and "body" ONLY
Example: { "headers": {"Content-Type":"application/json"}, "body":"...", "statusCode":200 }
See http://amzn.to/2lY4oQB
(under the heading Output Format of a Lambda Function for Proxy Integration)
*/
Map<String, Object> headers = new HashMap<>();
headers.put("Content-Type", "application/json");
headers.put("x-request-id", context.getAwsRequestId());
retval.put("headers", headers);
retval.put("statusCode", httpStatus);
retval.put("body", bodyAsJson);
return retval;
}
}
The AWS documentation provides a Java example which uses inputStream and outputStream and takes a lot more code: http://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-create-api-as-simple-proxy-for-lambda.html#api-gateway-proxy-integration-lambda-function-java
I like this version better because is simpler and shorter.
More comprehensive example here:
https://github.com/sylnsr/boilerplate-code/blob/master/java/aws/LambdaAPIGateway.java
