Pippo : WebSocket

How to use

Pippo allows you to use WebSocket in your application in an easy and uniform mode. You use the same interface for all major embedded web server supported by Pippo builtin (Jetty, Tomcat and Undertow).

The Application class contains a method with the signature:

public void addWebSocket(String path, WebSocketHandler webSocketHandler);

WebSocketHandler is an interface (functional) that contains one method

void onMessage(WebSocketContext webSocketContext, String message);

and some default methods.

To add an echo application based on websocket you should write something similar with:

// add web socket
addWebSocket("/ws/echo", (webSocketContext, message) -> {
    try {
        webSocketContext.sendMessage(message);
    } catch (IOException e) {
        e.printStackTrace();
    }
});

If you need more control you can override other methods available in WebSocketHandler:

addWebSocket("/ws/echo", new WebSocketHandler() {

    @Override
    public void onMessage(WebSocketContext webSocketContext, String message) {
        System.out.println("TestWebSocket.onMessage");
        System.out.println("message = " + message);
        try {
            webSocketContext.sendMessage(message);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onMessage(WebSocketContext webSocketContext, byte[] message) {
        System.out.println("TestWebSocket.onMessage");
    }

    @Override
    public void onOpen(WebSocketContext webSocketContext) {
        System.out.println("TestWebSocket.onOpen");
    }

    @Override
    public void onClose(WebSocketContext webSocketContext, int closeCode, String message) {
        System.out.println("TestWebSocket.onClose");
    }

    @Override
    public void onTimeout(WebSocketContext webSocketContext) {
        System.out.println("TestWebSocket.onTimeout");
    }

    @Override
    public void onError(WebSocketContext webSocketContext, Throwable t) {
        System.out.println("TestWebSocket.onError");
    }

});

In above example, I used a standard Route to serve the index.html file that contains the script block with the websocket client side:

GET("/", routeContext -> {
    try {
        routeContext.send(IoUtils.toString(WebSocketApplication.class.getResourceAsStream("/index.html")));
    } catch (IOException e) {
        e.printStackTrace();
    }
});

// OR

DirectoryHandler directoryHandler = new DirectoryHandler("/", new File("src/main/resources"));
GET(directoryHandler.getUriPattern(), directoryHandler);

Note A functional demo is available to pippo-demo-websocket.

Pippo Micro Java Web Framework

WebSocket

How to use