Author: Paul Cowan
Level: Intermediate
Technologies: Web Socket, CDI Events, JSON, SSL
Summary: Demonstrates use of a Javascript WebSocket client, WebSocket configuration, programmatic binding, and secure WebSocket. Target Product: WildFly
Source: https://github.com/wildfly/quickstart/
The websocket-client
quickstart demonstrates how to use the Java API for WebSockets to create Java client endpoint connected to a remote WebSocket server.
The example is modeled as a relay between a frontend WebSocket server endpoint and a backend WebSocket client endpoint.
Message Flow:
(Browser Javascript WebSocket Client) <-> (WildFly WebSocket Server Endpoint) <-> (WildFly Websocket Client Endpoint) <-> (Remote WebSocket Echo Server)
CDI events are used to pass messages between the frontend and backend. A single backend WebSocket client endpoint is shared for all frontend clients.
The remote WebSocket server must be an Echo server; a simple WebSocket server that echos back messages the client sends for the purpose of testing. Such a server is publicly available at ws://echo.websocket.org, but any echo server will work.
Frontend
does not use WebSocket annotations because it demonstrates how to use ServerEndpointConfig
to modify the default Configurator
to use an application scoped Endpoint, and how to deploy the Endpoint programatically.
Backend
does not use WebSocket annotations because it demonstrates how to use ClientEndpointConfig
to configure the WebSocket client to connect to a secure (wss) WebSocket.
The application this project produces is designed to be run on WildFly Application Server 11 or later.
All you need to build this project is Java 8.0 (Java SDK 1.8) or later and Maven 3.3.1 or later. See Configure Maven for WildFly 11 to make sure you are configured correctly for testing the quickstarts.
In the following instructions, replace WILDFLY_HOME
with the actual path to your WildFly installation. The installation path is described in detail here: Use of WILDFLY_HOME and JBOSS_HOME Variables.
For Linux: WILDFLY_HOME/bin/standalone.sh
For Windows: WILDFLY_HOME\bin\standalone.bat
mvn clean package wildfly:deploy
target/websocket-client.war
to the running instance of the server.Access the running application in a browser at the following URL: http://localhost:8080/websocket-client/
You are presented with the WebSocket Echo Replay
page confirming the connection to the remote WebSocket Echo server.
Connecting to ws://localhost:8080/websocket-client/relay
RECV: Opened frontend session FRONTEND_SESSION_ID
Type a message in the text input field at the bottom of the page and click Send
. The message is processed and the form displays the relayed results. The message This is a test
was used in the following example.
SEND: This is a test
RECV: BROADCAST: Connecting to backend wss://echo.websocket.org
RECV: BROADCAST: Opened backend session BACKEND_SESSION_ID
RECV: Sending message from frontend session FRONTEND_SESSION_ID
RECV: Received message from backend session BACKEND_SESSION_ID
RECV: This is a test
mvn wildfly:undeploy
You can also start the server and deploy the quickstarts or run the Arquillian tests from Eclipse using JBoss tools. For general information about how to import a quickstart, add a WildFly server, and build and deploy a quickstart, see Use JBoss Developer Studio or Eclipse to Run the Quickstarts.
If you want to debug the source code of any library in the project, run the following command to pull the source into your local repository. The IDE should then detect it.
mvn dependency:sources