.js

package com.serverless;
...
import com.serverless.dal.Product;

public class ListProductsHandler implements RequestHandler<Map<String, Object>, ApiGatewayResponse> {

	private final Logger logger = Logger.getLogger(this.getClass());

	@Override
	public ApiGatewayResponse handleRequest(Map<String, Object> input, Context context) {
    try {
        // get all products
        List<Product> products = new Product().list();

        // send the response back
        return ApiGatewayResponse.builder()
    				.setStatusCode(200)
    				.setObjectBody(products)
    				.setHeaders(Collections.singletonMap("X-Powered-By", "AWS Lambda & Serverless"))
    				.build();
    } catch (Exception ex) {
        logger.error("Error in listing products: " + ex);

        // send the error response back
        ...
    }
  }
}