Create servlet to process the submitted data

Launch your aem-banking project in IntelliJ.
Create a simple servlet to output the submitted data to the log file.Make sure the code is in the core project as shown in the screenshot below

package com.aem.bankingapplication.core.servlets;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.SlingHttpServletResponse;
import org.apache.sling.api.servlets.SlingAllMethodsServlet;
import javax.servlet.Servlet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.osgi.service.component.annotations.Component;
@Component(service = { Servlet.class}, property = {"sling.servlet.methods=post","sling.servlet.paths=/bin/formstutorial"})
public class HandleFormSubmissison extends SlingAllMethodsServlet {
    private static final Logger log = LoggerFactory.getLogger(HandleFormSubmissison.class);
    protected void doPost(SlingHttpServletRequest request,SlingHttpServletResponse response) {
        log.debug("Inside my formstutorial servlet");
        log.debug("The form data I got was "+request.getParameter("jcr:data"));
    }
}

Create Custom submit handler

Create your custom submit action in the apps/bankingapplication folder the same way you would create in the earlier versions of AEM Forms. For the purpose of this tutorial, I create a folder called SubmitToAEMServlet under the apps/bankingapplication node in the CRX repository.

The following code in the post.POST.jsp simply forwards the request to the servlet mounted on /bin/formstutorial. This is the same servlet that was created in the earlier step

com.adobe.aemds.guide.utils.GuideSubmitUtils.setForwardPath(slingRequest,"/bin/formstutorial",null,null);

In your AEM project in IntelliJ right click the apps/bankingapplication folder and select New | Package and type in SubmitToAEMServlet after the apps.bankingapplication in the new package dialog box. Right-click the SubmitToAEMServlet node and select repo | Get Command to synchronize the AEM project with the AEM server repository.

Configure Adaptive Form

You can now configure any Adaptive Form to submit to this custom submit handler called Submit To AEM Servlet

Next Steps

Register servlet using resource type