package com.example;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import io.undertow.Handlers;
import io.undertow.Undertow;
import io.undertow.servlet.Servlets;
import io.undertow.servlet.api.DeploymentInfo;
import io.undertow.servlet.api.DeploymentManager;

public class RedirectServer {

	public static void main(String[] args) throws ServletException {
		DeploymentInfo servletBuilder = Servlets.deployment()
				.setClassLoader(RedirectServer.class.getClassLoader())
				.setContextPath("/myapp")
				.setDeploymentName("test.war")
				.addServlets(
						Servlets.servlet("redirect", RedirectServlet.class).addMapping("/*"));

		DeploymentManager manager = Servlets.defaultContainer().addDeployment(servletBuilder);
		manager.deploy();
		Undertow server = Undertow.builder()
				.addHttpListener(8080, "localhost")
				.setHandler(Handlers.path(Handlers.proxyPeerAddress(manager.start())))
				.build();
		server.start();
	}

	@SuppressWarnings("serial")
	static class RedirectServlet extends HttpServlet {

		@Override
		protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
			resp.sendRedirect("/redirected");
		}

	}

}

curl -v 127.0.0.1:8080/myapp/redirect -H 'X-Forwarded-Proto: https' -H 'X-Forwarded-Host: api.example.com' -H 'X-Forwarded-Port: 443'
*   Trying 127.0.0.1...
* Connected to 127.0.0.1 (127.0.0.1) port 8080 (#0)
> GET /myapp/redirect HTTP/1.1
> Host: 127.0.0.1:8080
> User-Agent: curl/7.46.0
> Accept: */*
> X-Forwarded-Proto: https
> X-Forwarded-Host: api.example.com
> X-Forwarded-Port: 443
>
< HTTP/1.1 302 Found
< Connection: keep-alive
< Location: https://127.0.0.1:8080/redirected
< Content-Length: 0
< Date: Thu, 30 Jun 2016 10:04:42 GMT
<
* Connection #0 to host 127.0.0.1 left intact