Editing Jakarta Transactions (section)

===UserTransaction interface===
The {{Javadoc:EE|package=javax.transaction|javax/transaction|UserTransaction}} interface provides the application the
ability to control transaction boundaries programmatically. This interface may be used
by Java client programs or EJB beans.

The {{Javadoc:EE|javax/transaction|UserTransaction|begin()}} method starts a global transaction and associates the
transaction with the calling thread. The transaction-to-thread association is managed
transparently by the Transaction Manager.

Support for nested transactions is not required. The UserTransaction.begin method
throws the NotSupportedException when the calling thread is already associated
with a transaction and the transaction manager implementation does not support nested
transactions.

Transaction context propagation between application programs is provided by the
underlying transaction manager implementations on the client and server machines.
The transaction context format used for propagation is protocol dependent and must be
negotiated between the client and server hosts. For example, if the transaction manager
is an implementation of the [[Java transaction service|JTS]] specification, it will use the transaction context
propagation format as specified in the CORBA OTS 1.1 specification. Transaction
propagation is transparent to application programs.