The is a chat application (a canonical use case for WebSocket) built using the Java WebSocket API (JSR 356). This is meant to help understand the API usage and try it hands on (this is not a full-blown chat service)
- Uses the Tyrus implementation for the core logic
- Leverages the Grizzly container support available in Tyrus
- Packaged as a standalone JAR
The application is a Maven project
- To build, just execute
mvn clean installwhich will produce an independent (fat/uber) JAR - Run it using
java -jar target/websocket-chat.jar
Here is what you can do with the chat application
- Join the chat room
- Send public messages
- Send private messages
- Get notified about new users joining
- Leave the chat room
- Get notified another user leaves the chat room
Before you explore the source code yourself, here is quick overview
| Class(es) | Category | Description |
|---|---|---|
ChatServer |
Core | It contains the core business logic of the application |
WebSocketServerManager |
Bootstrap | Manages bootstrap and shutdown process of the WebSocket container |
ChatMessage,DuplicateUserNotification,LogOutNotification,NewJoineeNotification,Reply,WelcomeMessage |
Domain objects | Simple POJOs to model the application level entities |
ChatMessageDecoder |
Decoder | Converts chats sent by users into Java (domain) object which can be used within the application |
DuplicateUserMessageEncoder, LogOutMessageEncoder,NewJoineeMessageEncoder,ReplyEncoder,WelcomeMessageEncoder |
Encoder(s) | Converts Java (domain) objects into native (text) payloads which can be sent over the wire using the WebSocket protocol |
Unit tests: The unit tests use the Java client API implementation in Tyrus
You would need a WebSocket client for this example - try the Simple WebSocket Client which is a Chrome browser plugin. Here is a transcript
- Users foo and bar join the chatroom. To do so, you need to connect to the WebSocket endpoint URL e.g.
ws://localhost:8080/chat/foo/(do the same for user bar). foo gets notified about bar - User john joins (
ws://localhost:8080/chat/john/). foo and bar are notified - foo sends a message to everyone (public). Both bar and john get the message
- bar sends a private message to foo. Only foo gets it
- In the meanwhile, john gets bored and decides to leave the chat room. Both foo and bar get notified