» Create custom servlet as named FlagtickCustomServlet

package com.flagtick.core.servlets;

import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.SlingHttpServletResponse;
import org.apache.sling.api.servlets.HttpConstants;
import org.apache.sling.api.servlets.SlingSafeMethodsServlet;
import org.osgi.framework.Constants;
import org.osgi.service.component.annotations.Component;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.Servlet;
import java.io.IOException;

@Component(service = Servlet.class, property = {
        Constants.SERVICE_DESCRIPTION + "= HTTP servlet",
        "sling.servlet.methods=" + HttpConstants.METHOD_GET,
        "sling.servlet.paths=" + "/bin/flagtick/httpcall" }
)
public class FlagtickCustomServlet extends SlingSafeMethodsServlet {

    private static final long serialVersionUID = -2014397651676211439L;
    private static final Logger log = LoggerFactory.getLogger(FlagtickCustomServlet.class);

    @Override
    protected void doGet(SlingHttpServletRequest request, SlingHttpServletResponse response) {
        try {
            response.getWriter().println("Hello World");
        } catch (IOException e) {
            log.error(e.getCause().getMessage());
        }
    }
}

» Right now, we just update code implementation in Java side, let execute commands in core module.

mvn clean install -PautoInstallBundle

Note: The above command automatically builds and deploys the bundle to your AEM instance running on localhost:4502

» Here is screenshot

» Testing with Postman, you need select Basic Auth (enter username and password are admin)