Websocket Component

Available as of Camel 2.10

The websocket component provides websocket endpoints for communicating with clients using websocket.

URI format

websocket://hostname[:port][/resourceUri][?options]

You can append query options to the URI in the following format, ?option=value&option=value&...

Options

None.

Message Headers

The websocket component uses 2 headers to indicate to either send messages back to a single/current client, or to all clients.

Key	Description
`WebsocketConstants.SEND_TO_ALL`	Sends the message to all clients which are currently connected. You can use the `sendToAll` option on the endpoint instead of using this header.
`WebsocketConstants.CONNECTION_KEY`	Sends the message to the client with the given connection key.

Component Options

The WebsocketComponent must be configured prior to use, to setup host, to act as a websocket server.

Option	Default	Description
Host	0.0.0.0	The hostname.
Port	9292	The port number.
StaticResources	`null`	Path for static resources such as index.html files etc.

Endpoint Options

The WebsocketEndpoint can be configured prior to use

Option	Default	Description
sendToAll	`null`	To send to all websocket subscribers. Can be used to configure on endpoint level, instead of having to use the `WebsocketConstants.SEND_TO_ALL` header on the message.

Usage

In this example we let Camel exposes a websocket server which clients can communicate with. The websocket server uses the default host and port, which would be 0.0.0.0:9292.
The example will send back an echo of the input. To send back a message, we need to send the transformed message to the same endpoint "websocket://echo". This is needed
because by default the messaging is InOnly.

// expose a echo websocket client, that sends back an echo
from("websocket://echo")
    .log(">>> Message received from WebSocket Client : ${body}")
    .transform().simple("${body}${body}")
    // send back to the client, by sending the message to the same endpoint
    // this is needed as by default messages is InOnly
    // and we will by default send back to the current client using the provided connection key
    .to("websocket://echo");

This example is part of an unit test, which you can find here. As a client we use the AHC library which offers support for web socket as well.

[CONF] Apache Camel > Websocket

Websocket

Page edited by Claus Ibsen

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