Handling the Loss of Thin Client Connections

When a thin client connection is lost, the presentation client displays a message box that has one of the following button combinations, so that you can programmatically retry the connection or programmatically close it.

• Three buttons

  • Exit, to terminate the application.

  • Retry, to attempt 10 further connection attempts over 10 seconds. If the 10 reconnection attempts all fail, the same message box is displayed again.

    If a connection was successfully made but the session cannot be continued (for example, if the application server was restarted), the Retry button is not displayed.

  • Restart, which initiates another copy of the application and terminates the current session.

    This button is displayed only if the application was not started programmatically by JADE logic. Applications programmatically initiated (for example, by calling the Application class startAppMethod, startAppMethodWithString, or startApplicationWithParameter method) cannot be restarted, because the mechanisms required cannot be guaranteed or reconstructed.

    If the start also fails to establish another connection, another message box is displayed. (See the Two buttons (when a retry is not an option) item, later in this list.)

• Two buttons (when a restart is not an option)

  • Exit

  • Retry

• Two buttons (when a retry is not an option)

  • Exit

  • Restart

• One button

  • OK, when the only option is to terminate. (The displayed message includes the text You must restart the Application.)

The full process is therefore as follows.

1. When the connection is lost, JADE attempts to reconnect for the timeout value specified in the ReconnectTimeout parameter in the [JadeThinClient] section of the JADE initialization file on a local presentation client (which defaults to 40 seconds).

2. If no connection attempt succeeds in the reconnect timeout period, the appropriate message box (documented in the list earlier in this section) is displayed.

3. For a retry to succeed, the setup requires that the application server waits for an appropriate length of time before giving up on the reconnection and terminating the application.

4. If a connection succeeds but the session cannot be continued because the application server has already terminated the session, the message box that is displayed will not have a Retry button.