Building a HTTP Endpoint with Eclipse Vert.x

cescoffier

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01 Introduction

02 Vert.x

03 Creating a HTTP server

04 Producing JSON

05 Getting query parameters

06 Observing the event loop

07 Summary

Previous: Creating a HTTP server Next: Getting query parameters

Producing JSON

JSON is everywhere Today. So let's jump into the train too and produce a JSON result. To do this, Vert.x provides:

the Json class providing object mapping methods,
the JsonObject and JsonArray allowing to create and manipulate JSON structures.

We are going to use this second approach to return something like:

{
    "message": "hello"
}

This object can be easily created using: new JsonObject().put("message", "hello"). Then, we just need to encode this JSON structure into the HTTP response:

Producing JSON

package io.vertx.playground;
 
import io.vertx.core.Vertx;
import io.vertx.core.json.JsonObject;
 
public class HttpServerJsonExample {
 
    public static void main(String... args) {
       Vertx vertx = Vertx.vertx(); 
 
       vertx.createHttpServer()
        .requestHandler(req -> {
            JsonObject json = new JsonObject()
                .put("message", "hello");
           req.response()
                .putHeader("Content-Type", "application/json; charset=UTF8")
                .end(json.encodePrettily());
        })
        .listen(8080);
    }
 
}