com.SIMRacingApps.servlets

Class DataStreaming

java.lang.Object

javax.websocket.Endpoint

com.SIMRacingApps.servlets.DataStreaming

All Implemented Interfaces:

javax.websocket.MessageHandler, javax.websocket.MessageHandler.Whole<java.lang.String>

public class DataStreaming
extends javax.websocket.Endpoint
implements javax.websocket.MessageHandler.Whole<java.lang.String>

This class implements the "/DataStreaming" interface for the HTTP Web Socket protocol. You must call the "/Data" service first using the POST method to subscript to the data to receive events on. For example: when using a JavaScript client, use the WebSocket() constructor to create a connection.

Once the connection is opened, it listens for a message on the socket in the form of "sessionid;interval". Once received, the data is transmitted back to the client every "interval". The client does not have to poll for the data. "interval" is in milliseconds and defaults to 100ms.

Since:

1.0

Author:

Jeffrey Gilliam

Copyright:

Copyright (C) 2015 - 2024 Jeffrey Gilliam

License:

Apache License 2.0

Nested Class Summary

Nested classes/interfaces inherited from interface javax.websocket.MessageHandler

javax.websocket.MessageHandler.Partial<T>, javax.websocket.MessageHandler.Whole<T>

Constructor Summary

Constructors

Constructor and Description
DataStreaming()

Method Summary

Modifier and Type	Method and Description
void	onClose(javax.websocket.Session session, javax.websocket.CloseReason closeReason) The user closes the connection.
void	onMessage(java.lang.String params) When a user sends a message to the server, this method will intercept the message and allow us to react to it.
void	onOpen(javax.websocket.Session session, javax.websocket.EndpointConfig config) OnOpen allows us to intercept the creation of a new session.

Methods inherited from class javax.websocket.Endpoint

onError

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DataStreaming

public DataStreaming()

Method Detail

onOpen

public void onOpen(javax.websocket.Session session,
                   javax.websocket.EndpointConfig config)

OnOpen allows us to intercept the creation of a new session. The session class allows us to send data to the user. In the method onOpen, we'll let the user know that the handshake was successful.

Specified by:

onOpen in class javax.websocket.Endpoint

Parameters:

session - An instance to a Session.

onClose

public void onClose(javax.websocket.Session session,
                    javax.websocket.CloseReason closeReason)

The user closes the connection. Note: you can't send messages to the client from this method

Overrides:

onClose in class javax.websocket.Endpoint

Parameters:

session - An instance to a Session.

closeReason - The reason the socket was closed.

onMessage

public void onMessage(java.lang.String params)

When a user sends a message to the server, this method will intercept the message and allow us to react to it. For now the message is read as a String.

Specified by:

onMessage in interface javax.websocket.MessageHandler.Whole<java.lang.String>

Parameters:

params - A semicolon separated list of parameters. The first parameter is the session id.