Transactions for Entity Beans
  • Entity beans are intended to work within transactions
  • However, unlike most transactional systems, transactions are not managed by code
    • The transactional behaviour is specified in the deployment descriptor
    • The deployment descriptor is an XML file supplied with the bean(s)
    • Example 18 shows a portion of the Auction system's deployment descriptor
  • Descriptor specifies Required as the transactional attribute for all methods on Bid
    • This is the normal specification for an entity bean
    • Methods must execute in a transaction
      • If there is no transaction at the start of the method, the container starts one
      • If there is a transaction, it is just used

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