SockJS eventbus client in Java for Vert.x

Question

is there a Java SockJS client for Vert.x available? Similar to the TCP/IP bridge, but based on SockJS. Reason is that we want a unified protocol stack, connecting clients to Vert.x. For JavaScript we can use vertx3-eventbus-client, which work great. We are looking now for a similar solution for Java.

tsegismont tsegismont · Accepted Answer · 2018-03-13T10:26:31

There isn't yet (work-in-progress). However you can write a basic client yourself using the Vert.x HttpClient:

open a websocket
send pings periodically to prevent the connection from being closed
register a handler
listen for messages

Here's an example:

client.websocket(HTTP_PORT, HTTP_HOST, "/eventbus/websocket", ws -> {
  JsonObject msg = new JsonObject().put("type", "ping");
  ws.writeFrame(io.vertx.core.http.WebSocketFrame.textFrame(msg.encode(), true));

  // Send pings periodically to avoid the websocket connection being closed
  vertx.setPeriodic(5000, id -> {
    JsonObject msg = new JsonObject().put("type", "ping");
    ws.writeFrame(io.vertx.core.http.WebSocketFrame.textFrame(msg.encode(), true));
  });

  // Register
  JsonObject msg = new JsonObject().put("type", "register").put("address", "my-address");
  ws.writeFrame(io.vertx.core.http.WebSocketFrame.textFrame(msg.encode(), true));

  ws.handler(buff -> {
    JsonObject json = new JsonObject(buff.toString()).getJsonObject("body");
    // Do stuff with the body
  });
});

If you need to work with different addresses then your handler will have to inspect the JSON object, not just get the body.

SockJS eventbus client in Java for Vert.x

1 Answers