Setting basic response http headers for REST resources on a simple Vertx Rest based app

Paris ApostolopoulosNovember 29th, 2015Last Updated: November 29th, 2015

0 316 1 minute read

I am new to Vert.x but as a Java developer (die hard) I find it much more enjoyable and promising comparing to NodeJS or whatever – Reactor based frameworks/libraries. So I was going through implementing a very simple Restful API, using Vert.x.

My problem for today is that I wanted to include some certain HttpHeaders in most (all) of my , responses. For example set the Content-type to “application/json”. In the future maybe add some others.

I was kind of wondering around as a Vert.x newbie, then I kind of realized that what is was eventually suggested in this blog post (See the use of BodyHandler) would actually work for me.

So I had my main VertxMain java app where I register my MyWebVerticleApp.

package com.javapapo.vertxweb;
 
import io.vertx.core.Vertx;
import io.vertx.core.VertxOptions;
 
/**
 * Created by <a href="mailto:javapapo@mac.com">javapapo</a> on 15/11/15.
 */
public class VertxEngineMain {
    public static void main(String[] args) {
        VertxOptions opts = new VertxOptions();
        Vertx vertx = Vertx.vertx(opts);
        vertx.deployVerticle(new MyWebVerticleApp());
    }
 
 
 
}

Then I have created a small handler, I call it BaseResponseHandler, that eventually adds the HttpHeader in my responses.

package com.javapapo.vertxweb.handlers;
 
import io.netty.handler.codec.http.HttpResponse;
import io.vertx.core.Handler;
import io.vertx.core.http.HttpHeaders;
import io.vertx.core.http.HttpServerRequest;
import io.vertx.core.http.HttpServerResponse;
import io.vertx.ext.web.RoutingContext;
 
/**
 * Created by <a href="mailto:javapapo@mac.com">javapapo</a> on 27/11/15.
 */
public class BaseResponseHandler implements Handler<RoutingContext>{
 
    @Override
    public void handle(RoutingContext context) {
        HttpServerResponse response = context.response();
        response.putHeader(HttpHeaders.CONTENT_TYPE.toString(), "application/json");
        //other stuff!
        response.setChunked(true);
        context.next();
    }
 
}

Then in my MyWebVerticle I just register the handler to be invoked all the time, in the router chaining.

package com.javapapo.vertxweb;
 
import com.javapapo.vertxweb.handlers.BaseResponseHandler;
import com.javapapo.vertxweb.handlers.StatusHandler;
import io.vertx.core.AbstractVerticle;
import io.vertx.core.Future;
import io.vertx.core.http.HttpServer;
import io.vertx.core.http.HttpServerResponse;
import io.vertx.ext.web.Route;
import io.vertx.ext.web.Router;
import io.vertx.ext.web.handler.BodyHandler;
 
/**
 * Created by <a href="mailto:javapapo@mac.com">javapapo</a> on 16/11/15.
 */
public class MyWebVerticleApp extends AbstractVerticle {
    @Override
    public void start(Future<Void> fut) {
        HttpServer server = vertx.createHttpServer();
        Router router = Router.router(vertx);
        //enable the base response handler overall!
        router.route().handler(new BaseResponseHandler());
        router.route("/status/").handler(new StatusHandler());
        server.requestHandler(router::accept).listen(8080);
    }
}