Package org.jgrapes.webconsole.base

Class ConsoleConnection

java.lang.Object
org.jgrapes.core.Subchannel.DefaultSubchannel
org.jgrapes.io.IOSubchannel.DefaultIOSubchannel
org.jgrapes.webconsole.base.ConsoleConnection
All Implemented Interfaces:
Associator, Channel, Eligible, Subchannel, IOSubchannel
public final class ConsoleConnection extends IOSubchannel.DefaultIOSubchannel
The server side representation of a window in the browser that displays a console page (a console connection).

An instance is created when a new console window opens the WebSocket connection to the server for the first time. If the connection between the browser and the server is lost (e.g. due to temporary network failure), the console code in the browser tries to establish a new WebSocket connection to the same, already existing ConsoleConnection. The ConsoleConnection object is thus independent of the WebSocket connection that handles the actual transfer of notifications.

WebConsole Connection

To allow reconnection and because there is no reliable way to be notified when a window in a browser closes, Closed events from the network are ignored and ConsoleConnections remain in an open state as long as they are in use. Only if no data is received (i.e. refresh() isn’t called) for the time span configured with ConsoleWeblet.setConnectionNetworkTimeout(java.time.Duration) a timer closes the connection by calling the close() method. (Method isConnected() can be used to check the connection state.) In order to keep the console connection in an open state while the connection is inactive, i.e. no data is sent due to user activity, the SPA automatically generates refresh messages as configured with ConsoleWeblet.setConnectionRefreshInterval(Duration).

ConsoleConnection implements the IOSubchannel interface. This allows the instances to be used as channels for exchanging console connection scoped events with the WebConsole component. The upstream channel (see upstreamChannel()) is the channel of the WebSocket. It may be unavailable if the WebSocket connection has been interrupted and not (yet) re-established. The IOSubchannel’s response EventPipeline must be used to send events (responses) to the console connection in the browser. No other event pipeline may be used for this purpose, else messages will interleave.

To avoid having too many open WebSockets with inactive console connections, a maximum inactivity time can be configured with ConsoleWeblet.setConnectionInactivityTimeout(Duration). The SPA always checks if the time since the last user activity has reached or exceeded the configured limit before sending the next refresh message. In case it has, the SPA stops sending refresh messages and displays a “suspended” dialog to the user.

When the user chooses to resume, a new WebSocket is opened by the SPA. If the Session used before the idle timeout is still available (hasn’t reached its idle timeout or absolute timeout) and refers to a ConsoleConnection not yet closed, then this ConsoleConnection is reused, else the SPA is reloaded.

As a convenience, the ConsoleConnection provides direct access to the browser session, which can usually only be obtained from the HTTP event or WebSocket channel by looking for an association of type Session.

  • Method Details

    • byConsole

      public static Set<ConsoleConnection> byConsole(WebConsole console)
      Return all connections that belong to the given console as a new unmodifiable set.
      Parameters:
      console - the console
      Returns:
      the sets the

    • setTimeout

      public ConsoleConnection setTimeout(long timeout)
      Changes the timeout for this ConsoleConnection to the given value.
      Parameters:
      timeout - the timeout in milli seconds
      Returns:
      the console connection for easy chaining

    • expiresAt

      public Instant expiresAt()
      Returns the time when this connection will expire.
      Returns:
      the instant

    • refresh

      public void refresh()
      Resets the ConsoleConnection’s timeout.

    • close

      public void close()
      Close this connection.

      The connection is removed from the set of open connections and a Closed event is fired on the connection.

    • isOpen

      public boolean isOpen()
      Checks if the console connection is open.
      Returns:
      true, if is open

    • isConnected

      public boolean isConnected()
      Checks if a network connection with the browser exists.
      Returns:
      true, if is connected

    • webletChannel

      public Channel webletChannel()
      Provides access to the weblet’s channel.
      Returns:
      the channel

    • setUpstreamChannel

      public ConsoleConnection setUpstreamChannel(IOSubchannel upstreamChannel)
      Sets or updates the upstream channel.

      This method should only be invoked by the creator of the ConsoleConnection, by default the ConsoleWeblet.

      Parameters:
      upstreamChannel - the upstream channel (WebSocket connection)
      Returns:
      the console connection for easy chaining

    • setSessionSupplier

      public ConsoleConnection setSessionSupplier(Supplier<Optional<Session>> sessionSupplier)
      Sets or updates associated browser session.

      This method should only be invoked by the creator of the ConsoleConnection, by default the ConsoleWeblet.

      Parameters:
      sessionSupplier - the browser session supplier
      Returns:
      the console connection for easy chaining

    • upstreamChannel

      public IOSubchannel upstreamChannel()
      Returns:
      the upstream channel

    • session

      public Session session()
      Returns:
      the browser session

    • supportedLocales

      public Set<Locale> supportedLocales()
      Returns the supported locales.
      Returns:
      the set of locales supported by the console

    • locale

      public Locale locale()
      Return the console connection’s locale.

      The locale is initialized from the browser session’s locale.

      Returns:
      the locale

    • setLocale

      public ConsoleConnection setLocale(Locale locale)
      Sets the locale for this console connection.
      Parameters:
      locale - the locale
      Returns:
      the console connection

    • toString

      public String toString()
      Overrides:
      toString in class Subchannel.DefaultSubchannel