An example of dynamic routing based on cookies

CookieRoutingExample.java

package io.activej.launchers.http;

import io.activej.http.AsyncServlet;
import io.activej.http.HttpResponse;
import io.activej.http.RoutingServlet;
import io.activej.inject.annotation.Named;
import io.activej.inject.annotation.Provides;

public final class CookieRoutingExample extends HttpServerLauncher {

	private static final String COOKIE = "SERVLET_NUMBER";

	@Provides
	AsyncServlet mainServlet(@Named("First") AsyncServlet firstServlet, @Named("Second") AsyncServlet secondServlet) {
		return RoutingServlet.create()
				.map("/*", request -> {
					String servletNumberCookier = request.getCookie(COOKIE);
					if (servletNumberCookier == null) {
						return HttpResponse.ofCode(400).withPlainText("Cookie '" + COOKIE + "' is missing");
					}
					if ("1".equals(servletNumberCookier)) {
						return firstServlet.serve(request);
					} else if ("2".equals(servletNumberCookier)) {
						return secondServlet.serve(request);
					} else {
						return HttpResponse.ofCode(400).withPlainText("Unknown servlet number");
					}
				});
	}

	@Provides
	@Named("First")
	AsyncServlet firstServlet() {
		return request -> HttpResponse.ok200().withHtml("<h1>This is servlet #1</h1>");
	}

	@Provides
	@Named("Second")
	AsyncServlet secondServlet() {
		return request -> HttpResponse.ok200().withHtml("<h1>This is servlet #2</h1>");
	}

	public static void main(String[] args) throws Exception {
		new CookieRoutingExample().launch(args);
	}
}