org.mobicents.servlet.sip.core.dispatchers
Class CancelRequestDispatcher

java.lang.Object
  org.mobicents.servlet.sip.core.dispatchers.MessageDispatcher
      org.mobicents.servlet.sip.core.dispatchers.RequestDispatcher
          org.mobicents.servlet.sip.core.dispatchers.CancelRequestDispatcher

public class CancelRequestDispatcher
extends RequestDispatcher

This class implements the logic for routing CANCEL requests along the application path followed by the INVITE.
CANCEL deserves a special treatment since they are routed hop by hop.

Algorithm used : We can distinguish 2 cases here as per spec :

• Applications that acts as User Agent or B2BUA 11.2.3 Receiving CANCEL : When a CANCEL is received for a request which has been passed to an application, and the application has not responded yet or proxied the original request, the container responds to the original request with a 487 (Request Terminated) and to the CANCEL with a 200 OK final response, and it notifies the application by passing it a SipServletRequest object representing the CANCEL request. The application should not attempt to respond to a request after receiving a CANCEL for it. Neither should it respond to the CANCEL notification. Clearly, there is a race condition between the container generating the 487 response and the SIP servlet generating its own response. This should be handled using standard Java mechanisms for resolving race conditions. If the application wins, it will not be notified that a CANCEL request was received. If the container wins and the servlet tries to send a response before (or for that matter after) being notified of the CANCEL, the container throws an IllegalStateException.
• Applications that acts as proxy : 10.2.6 Receiving CANCEL if the original request has not been proxied yet the container responds to it with a 487 final response otherwise, all branches are cancelled, and response processing continues as usual In either case, the application is subsequently invoked with the CANCEL request. This is a notification only, as the server has already responded to the CANCEL and cancelled outstanding branches as appropriate. The race condition between the server sending the 487 response and the application proxying the request is handled as in the UAS case as discussed in section 11.2.3 Receiving CANCEL.

Author:

Jean Deruelle

Field Summary

Fields inherited from class org.mobicents.servlet.sip.core.dispatchers.MessageDispatcher

APP_NOT_DEPLOYED, FINAL_RESPONSE, GENERATED_APP_KEY, MODIFIER, NO_APP_RETURNED, ROUTE_PARAM_DIRECTIVE, ROUTE_PARAM_NODE_HOST, ROUTE_PARAM_NODE_PORT, ROUTE_PARAM_PREV_APPLICATION_NAME, RR_PARAM_APPLICATION_NAME, RR_PARAM_PROXY_APP, sipApplicationDispatcher

Constructor Summary

CancelRequestDispatcher(SipApplicationDispatcher sipApplicationDispatcher)

Method Summary

void	dispatchMessage(javax.sip.SipProvider sipProvider, SipServletMessageImpl sipServletMessage) Responsible for routing and dispatching a SIP message to the correct application

Methods inherited from class org.mobicents.servlet.sip.core.dispatchers.RequestDispatcher

forwardRequestStatefully

Methods inherited from class org.mobicents.servlet.sip.core.dispatchers.MessageDispatcher

callServlet, callServlet, getConcurrencyModelExecutorService, makeAppSessionKey, securityCheck, sendErrorResponse

Methods inherited from class java.lang.Object

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

Constructor Detail

CancelRequestDispatcher

public CancelRequestDispatcher(SipApplicationDispatcher sipApplicationDispatcher)

Method Detail

dispatchMessage

public void dispatchMessage(javax.sip.SipProvider sipProvider,
                            SipServletMessageImpl sipServletMessage)
                     throws DispatcherException

Responsible for routing and dispatching a SIP message to the correct application

Specified by:

dispatchMessage in class MessageDispatcher

Parameters:

sipProvider - use the sipProvider to route the message if needed, can be null

sipServletMessage - the SIP message to route and dispatch

Throws:

DispatcherException