Path Parameters

Java Platform, Enterprise Edition (Java EE) 8
The Java EE Tutorial

Path Parameters

The ServerEndpoint annotation enables you to use URI templates to specify parts of an endpoint deployment URI as application parameters. For example, consider this endpoint:

@ServerEndpoint("/chatrooms/{room-name}")
public class ChatEndpoint {
   ...
}

If the endpoint is deployed inside a web application called chatapp at a local Java EE server in port 8080, clients can connect to the endpoint using any of the following URIs:

http://localhost:8080/chatapp/chatrooms/currentnews
http://localhost:8080/chatapp/chatrooms/music
http://localhost:8080/chatapp/chatrooms/cars
http://localhost:8080/chatapp/chatrooms/technology

Annotated endpoints can receive path parameters as arguments in methods annotated with @OnOpen, @OnMessage, and @OnClose. In this example, the endpoint uses the parameter in the @OnOpen method to determine which chat room the client wants to join:

@ServerEndpoint("/chatrooms/{room-name}")
public class ChatEndpoint {
   @OnOpen
   public void open(Session session,
                    EndpointConfig c,
                    @PathParam("room-name") String roomName) {
      // Add the client to the chat room of their choice ...
   }
}

The path parameters used as arguments in these methods can be strings, primitive types, or the corresponding wrapper types.

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