An event delivery library in Java?

Question

Hi, I'm looking for a library that will allow me to deliver simple text events from the server to the clients via sockets. Something simple and lightweight. I can write it myself, but decided to check if such thing exists first. The idea is that there's an application that generates events (such as order rejected or an internal error occurred) and acts as a server. Those events must be delivered to all connected clients in real-time. And a client is just a tray-icon app that pop ups the said event's text. Some simple UDP client/server. Does anyone know if there's a library out there for Java?

Thanks!

Answer 1

You should check out JBoss Netty and/or Apache MINA, which are both frameworks for building network protocols. It's debatable whether you consider them simple, although you can certainly build lightweight implementations with them.

Answer 2

This could be easily accomplished with XMPP pubsub. You can use Smack to connect to the server of your choice that supports pubsub (OpenFire, ejabberd, ...) so your application that creates the events is the publisher and the clients are all subscribers. It will require a 3rd party server to be used (many are open source), but it is just a single library for all client access. I have experience with OpenFire and it can be set up in about 15 minutes.

Many will not consider this light weight, but rolling your own pubsub solution is really not necessary.

Answer 3

There are many possible solutions, but if you want simple I suggest you try Hazelcast

It is as simple as using java.util.{Queue, Set, List, Map}. Just add the hazelcast.jar into your classpath and start coding.