The cause:

I discovered your mistake while attempting to transmit a JSON object from API Gateway to my Lambda function, and I followed the AWS documentation’s example Handler.java code.

The solution:

I just reconfigured the class principle from it as well to that in this situation.

public class Handler implements RequestHandler<Map<String, String>, String> {

In response to this:

public class Handler implements RequestHandler<Map<String, Object>, String> { 

Now I have a Map<String, Object> with all of my nested objects in it. It’s preferable to create your own unique object rather than digging through the map manually, although this method works for testing.

Remember to modify your handler if you’re using this:

@Override
public String handleRequest(Map<String, String> event, Context context) {

In response to this:

@Override
public String handleRequest(Map<String, Object> event, Context context) {

I hope to be of assistance to you. Goodluck to you!