Information Technology Reference
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F IG .9. EJBSync : method replay infrastructure.
class that implements EJBObject ) delegates a client invocation to the bean imple-
mentation (i.e., the class that implements SessionBean or EntityBean ), a top-level
method invocation is logged by creating a LogRecord EJB. For example, if an ap-
plication invokes the SSB newOrder method, and that method, in turn, invokes the
OrderHome.createOrder and a series of Order.addLineItem methods,
only newOrder (and its arguments) are logged. EJBSync is responsible for tracking
the dynamic method depth at which a given method executes. Note that only remote-
able EJBs support method logging using the EJBSync middleware. Local-only EJBs
do not have Handles that allow references to them to be saved persistently, and their
parameters are not restricted to serializable datatypes.
Sample 14 shows the signature of the newOrder method as specified in the Man-
ageOrder SSB. The bean developer implements this method to validate the input
parameters, and iterate over the set of line items in the order so as to interact with the
OrderHome , OrderLineHome , StockHome , and CustomerHome and place
the order. ManageOrder and its implementation are specified independently of any
container implementation or environment, and can be deployed to any EJB container.
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