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Copyright � 2003 Sun Microsystems, Inc. All rights reserved.
Copyright � 2005 BEA Systems, Inc. All rights reserved.
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Module Name : JSIP Specification
File Name : Transaction.java
Author : Phelim O'Doherty
Version Date Author Comments
1.1 08/10/2002 Phelim O'Doherty Initial version
1.2 12/15/2004 M. Ranganathan Clarified behavior of getDialog when
Phelim O'Doherty AUTOMATIC_DIALOG_SUPPORT is set to off.
Added two methods - set/getApplicationData
Added terminate method.
Transactions are a fundamental component of SIP. A transaction is a request
sent by a client transaction to a server transaction, along with all
responses to that request sent from the server transaction back to the client
transactions. User agents contain a transaction layer, as do stateful proxies.
Stateless proxies do not contain a transaction layer. This specification
provides the capabilities to allow either the SipProvider or SipListener to
handle transactional functionality.
This interface represents a generic transaction interface defining the methods
common between client and server transactions.
Gets the dialog object of this transaction object. A dialog only
exists for a transaction when a session is setup between a User Agent
Client and a User Agent Server, either by a 1xx Provisional Response
for an early dialog or a 200OK Response for a committed dialog.
- If the stack is configured with the AUTOMATIC_DIALOG_SUPPORT property set to
</it>ON</it> ( default behavior ) then the following behavior is defined:
- If the transaction is associated with an existing Dialog or could result
in a Dialog being created in the future (ie. the stack is configured
to recognize the method as a Dialog creating method or is one of the
natively supported dialog creating methods such as INVITE, SUBSCRIBE or
REFER), then the implementation must either associate the transaction
with the existing Dialog or create a Dialog with null state.
- If the Transaction is neither dialog creating nor can be associated with
an existing dialog, then the implementation must return null when the
application issues getDialog on the transaction.
- If the stack is configured with AUTOMATIC_DIALOG property set to </it>OFF</it>
then the stack does not automatically create a Dialog for a transaction nor does
it maintain an association between dialog and transaction on behalf of the
application. Hence this method will return null.
It is the responsibility of the application to create a Dialog and associate
it with the transaction when the response is sent.
- the dialog object of this transaction object or null if no
- See also:
Returns the current state of the transaction. Returns the current
TransactionState of this Transaction or null if a ClientTransaction has
yet been used to send a message.
- a TransactionState object determining the current state of the
Returns the current value of the retransmit timer in milliseconds used
to retransmit messages over unreliable transports for this transaction.
Sets the value of the retransmit timer to the newly supplied timer value.
The retransmit timer is expressed in milliseconds and its default value
is 500ms. This method allows the application to change the transaction
retransmit behavior for different networks. For example the gateway proxy,
the internal intranet is likely to be relatively uncongested
and the endpoints will be relatively close. The external network is the
general Internet. This functionality allows different retransmit times
for either side.
retransmitTimer - the new integer value of the retransmit timer
java.lang.UnsupportedOperationException if this method is not supported
by the underlying implementation.
Returns a unique branch identifer that identifies this transaction. The
branch identifier is used in the ViaHeader. The uniqueness property of
the branch ID parameter to facilitate its use as a transaction ID, was
not part of RFC 2543. The branch ID inserted by an element compliant
with the RFC3261 specification MUST always begin with the characters
"z9hG4bK". These 7 characters are used as a magic cookie, so that
servers receiving the request can determine that the branch ID was
constructed to be globally unique. The precise format of the branch
token is implementation-defined. This method should always return the
same branch identifier for the same transaction.
- the new branch that uniquely identifies this transaction.
Returns the request that created this transaction. The transaction state
machine needs to keep the Request that resulted in the creation of this
transaction while the transaction is still alive. Applications also need
to access this information, e.g. a forking proxy server may wish to
retrieve the original Invite request to cancel branches of a fork when
a final Response has been received by one branch.
- the Request message that created this transaction.
This method allows applications to associate application context with
the transaction. This specification does not define the format of this
data, this the responsibility of the application and is dependent
on the application. This capability may be useful for proxy servers
to associate the transaction to some application state. The context of
this application data is un-interpreted by the stack.
applicationData - un-interpreted application data.
Returns the application data associated with the transaction.This
specification does not define the format of this application specific
data. This is the responsibility of the application.
- application data associated with the transaction by the application.
Terminate this transaction and immediately release all stack resources
associated with it. When a transaction is terminated using this method,
a transaction terminated event is sent to the listener. If the
transaction is already associated with a dialog, it cannot be terminated
using this method. Instead, the dialog should be deleted to remove the
ObjectInUseException if the transaction cannot be terminated as
it is associated to a dialog.