Server WebSocket Clients, with Jetty

By: Guest Blogger Category:UncategorizedTag: Java, jetty:

Previously I discussed how to write a Server which uses a persistent WebSocket Client, using the Netty framework to make things go. Netty is configured through establishing a Channel Pipeline, which is great if you need a very flexible system for handling network input and output. For most projects however, this sort of power can be overkill.

Jetty

Jetty, among other great things, contains a WebSocketClient implementation. Getting this up and running is very simple: you?ll need a WebSocketClientFactory, where you can configure various settings, and a WebSocketClient which also has a bunch of settings to flip around to meet your needs. Once you have those, you?ll need a class that implements WebSocket.OnTextMessage ?and you?re pretty much done at this point.

The code for sending and receiving messages becomes equally simple:

@Override
public void send(Message message) {
    // a message is going out!
    String data = null;
    try {
        data = messageToString(message);
        connection.sendMessage(data);
    } catch (Exception e) {
        logger.error("Failed to send message! " + data, e);
    }
}
 
@Override
public void onMessage(String data) {
    // a message is coming in!
    logger.debug("message received: {}", data);
    try {
        Message message = stringToMessage(data);
        handleMessage(message);
    } catch (IOException e) {
        logger.error("Failed to parse incoming message! " + data, e);
    }
}