org.ptolemy.ptango.lib.webSocket

Class WebSocketEndpointManager

java.lang.Object

org.ptolemy.ptango.lib.webSocket.WebSocketEndpointManager

public class WebSocketEndpointManager
extends java.lang.Object

A singleton class that manages websocket endpoints and their connection openers (clients, servlets).

Since:

Ptolemy II 11.0

Version:

$Id$

Author:

Elizabeth Latronico

Pt.AcceptedRating:

Red (ltrnc)

Pt.ProposedRating:

Red (ltrnc)

Method Summary

Modifier and Type	Method and Description
void	closeServlets() Close all servlet websocket endpoints.
static WebSocketEndpointManager	getInstance() Get the factory instance, creating a new one if none created yet.
PtolemyWebSocketServlet	getServlet(java.lang.String path) Get the servlet for the given path.
static boolean	isRemoteURI(java.lang.String path) Return true if the path refers to a remote resource; false otherwise.
static boolean	isRemoteURI(java.net.URI uri) Return true if the path refers to a remote resource; false otherwise.
static boolean	isValidURI(java.lang.String path) Check if the given path is a valid URI.
void	openLocalServices(java.util.HashSet<WebSocketService> services, int portNumber) Open connections for the given set of services by looking up each service's affiliated endpoint and opening a connection for that endpoint.
static java.net.URI	pathToURI(java.lang.String path) Check the given path to see if it is a valid websocket URI and return a URI.
void	subscribe(WebSocketService service, java.lang.String path) Add the given service as a subscriber to the endpoint for this path.
void	unsubscribe(WebSocketService service, java.lang.String path) Remove the given service as a subscriber to the endpoint for this path.

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static WebSocketEndpointManager getInstance()

Get the factory instance, creating a new one if none created yet.

Returns:

The websocket client factory instance.

closeServlets

public void closeServlets()

Close all servlet websocket endpoints. Called by webserver in wrapup(). Synchronized to avoid interleaving opening and closing endpoints.

getServlet

public PtolemyWebSocketServlet getServlet(java.lang.String path)
                                   throws IllegalActionException

Get the servlet for the given path. If the servlet does not exist, create it. Called by the web server. Synchronized to avoid interleaving creating and deleting a servlet.

Parameters:

path - The URI the servlet should be mapped to.

Returns:

The servlet mapped to this path.

Throws:

IllegalActionException - Not thrown in this base class.

isRemoteURI

public static boolean isRemoteURI(java.lang.String path)
                           throws IllegalActionException

Return true if the path refers to a remote resource; false otherwise. Throw an exception if the path is not a valid URI.

Parameters:

path - The candidate URI.

Returns:

True if the path refers to a remote resource; false otherwise.

Throws:

IllegalActionException - If the path is not a valid URI.

isRemoteURI

public static boolean isRemoteURI(java.net.URI uri)

Return true if the path refers to a remote resource; false otherwise. Throw an exception if the path is not a valid URI.

Parameters:

uri - The candidate URI.

Returns:

True if the path refers to a remote resource; false otherwise.

isValidURI

public static boolean isValidURI(java.lang.String path)

Check if the given path is a valid URI. Return true if so; false otherwise.

Parameters:

path - The candidate URI.

Returns:

True if the path is a valid URI; false otherwise.

openLocalServices

public void openLocalServices(java.util.HashSet<WebSocketService> services,
                              int portNumber)
                       throws IllegalActionException

Open connections for the given set of services by looking up each service's affiliated endpoint and opening a connection for that endpoint. Assumes that these are local services. The WebServer uses this to open local services after it has started. Synchronized so that subscribing and unsubscribing are not interleaved.

Parameters:

services - The set of services to open connections for.

portNumber - The port number of the local web server.

Throws:

IllegalActionException - If one or more services cannot be opened.

pathToURI

public static java.net.URI pathToURI(java.lang.String path)
                              throws IllegalActionException

Check the given path to see if it is a valid websocket URI and return a URI. Throw an exception if the path is invalid.

Parameters:

path - The string representation of a websocket URI.

Returns:

The URI corresponding to this path string.

Throws:

IllegalActionException - If the path is not a valid URI.

subscribe

public void subscribe(WebSocketService service,
                      java.lang.String path)
               throws IllegalActionException

Add the given service as a subscriber to the endpoint for this path. Create a new endpoint if none exists for this path. Synchronized to avoid interleaved subscribing and unsubscribing. Generally, subscribers should subscribe in initialize() and should unsubscribe in wrapup().

Parameters:

service - The service to add as a subscriber.

path - The URL to subscribe to.

Throws:

IllegalActionException - If the URI is not valid.

See Also:

unsubscribe(WebSocketService, String)

unsubscribe

public void unsubscribe(WebSocketService service,
                        java.lang.String path)

Remove the given service as a subscriber to the endpoint for this path. Delete the endpoint if no services are associated with it. Synchronized to avoid conflicting writes to tables.

Parameters:

service - The service to remove as a subscriber

path - The URL to subscribe to

See Also:

subscribe(WebSocketService, String)