Aws Lambda: How to get query params from Api Gateway in lambda function implemented in Java

Question

Aws Lambda - How to get query params from Api Gateway in lambda function implemented in Java.

I have following code snippet :

package com.amazonaws.lambda.demo;

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;

public class LambdaFunctionHandler implements RequestHandler<String, String> {

    @Override
    public String handleRequest(String input, Context context) {
        context.getLogger().log("Input: " + input);

        // TODO: implement your handler
        return "Hello from " + input;
    }
}

How can i access query params if any in above handleRequest function.

score 7 · Answer 1 · edited Jan 15 '20 at 21:34

in pom.xml make sure "2.2.5" or newer version is specified here

<dependency>
  <groupId>com.amazonaws</groupId>
  <artifactId>aws-lambda-java-events</artifactId>
  <version>2.2.5</version>
</dependency>

Your java lambda class:

import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent;
import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyResponseEvent;

public class LambdaFunctionHandler
    implements RequestHandler<APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent> {
    @Override
    public APIGatewayProxyResponseEvent handleRequest(APIGatewayProxyRequestEvent input,
            Context context) {
        Map<String, String> inputParams = input.getPathParameters();

        APIGatewayProxyResponseEvent responseEvent = new APIGatewayProxyResponseEvent();
        responseEvent.setBody("body text");
        responseEvent.setStatusCode(200);
        return responseEvent;
    }
}

This did not work for me. Do I need to configure something else also? — Sunny, Apr 04 '20 at 07:19
AWS should use your answer for the official documentation; this is the most-complete 'template' that I've found for Lambdas for Java. It's minimal and gives you all of the types you need to process HTTP requests. Would upvote more than once if I could! — G M, May 31 '23 at 03:18

score 1 · Answer 2 · answered Jun 10 '21 at 09:13

Based on tgk23's answer above, I believe you are looking for the query parameters, not the path parameters:

public class LambdaFunctionHandler
        implements RequestHandler<APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent> {
    @Override
    public APIGatewayProxyResponseEvent handleRequest(APIGatewayProxyRequestEvent input, Context context) {
        Map<String, String> inputParams = input.getQueryStringParameters();
        for (Map.Entry<String, String> entry : inputParams.entrySet()) {
            LOGGER.info("param: " + entry.getKey() + "=" + entry.getValue());
        }

        APIGatewayProxyResponseEvent responseEvent = new APIGatewayProxyResponseEvent();
        responseEvent.setBody("body text");
        responseEvent.setStatusCode(200);
        return responseEvent;
    }
}

score 0 · Answer 3 · answered Sep 26 '17 at 16:55

0

You can try mapping everything you want in integration request body mapping template of API Gateway. Once you construct body mapping template then in the context of lambda you will get the excat json you have constructed.

Please find below link, which I have given a solution for similar kind of question,

https://stackoverflow.com/a/46407780/7666972

answered Sep 26 '17 at 16:55

Vijayanath Viswanathan

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Thanks Vijayanath , i will try this and come back. – Mohit Gupta Oct 03 '17 at 13:35

Aws Lambda: How to get query params from Api Gateway in lambda function implemented in Java

3 Answers3