Package com.sun.jdo.api.persistence.support

Class SynchronizationManager

  • All Implemented Interfaces:
    jakarta.transaction.Synchronization
    public class SynchronizationManager
extends Object
implements jakarta.transaction.Synchronization
    This class allows for multiple instances to be called at transaction completion, which JDO does not currently provide. JDO only provides for a single instance to be registered. This service exploits the JDO capability by registering an instance of SynchronizationManager with JDO and then calling each instance registered with itself.
    Version:
    1.0
    Author:
    Craig Russell

    • Field Detail

      • defaultCapacity

        protected static int defaultCapacity
        The default capacity of the List of Synchronizations.

      • synchronizations

        protected final List synchronizations
        The list of instances to synchronize. Duplicate registrations will result in the instance being called multiple times. Since we cannot depend on the caller implementing hashCode and equals, we cannot use a Set implementaion.

    • Constructor Detail

      • SynchronizationManager

        public SynchronizationManager​(int initialCapacity)
        Creates new SynchronizationManager instance specifying the initial capacity of the list of Synchronization instances.
        Parameters:
        initialCapacity - the initial capacity of the List of Synchronization instances

      • SynchronizationManager

        public SynchronizationManager()
        Creates new SynchronizationManager instance with a default capacity of the List of Synchronization instances.

      • SynchronizationManager

        protected SynchronizationManager​(PersistenceManager pm)
        Creates new SynchronizationManager instance and registers it with the persistence manager.
        Parameters:
        pm - the persistence manager managing this transaction

    • Method Detail

      • registerSynchronization

        public static void registerSynchronization​(jakarta.transaction.Synchronization instance,
                                           PersistenceManager pm)
        Register a new Synchronization with the current transaction.
        Parameters:
        instance - the instance to be registered
        pm - the persistence manager which manages this transaction

      • setDefaultCapacity

        public static void setDefaultCapacity​(int capacity)
        Specify the default capacity of the list of Synchronizations.
        Parameters:
        capacity - the default capacity of the List of Synchronizations

      • getSynchronizationManager

        protected static SynchronizationManager getSynchronizationManager​(PersistenceManager pm)
        Get the synchronization manager already registered with this persistence manager. If the synchronization instance is not of the proper class, then replace it with a new instance of the synchronization manager, and register the previous synchronization with the newly created synchronization manager.
        Parameters:
        pm - the persistence manager
        Returns:
        the synchronization manager

      • beforeCompletion

        public void beforeCompletion()
        This method will be called during transaction completion. Resource access is allowed. This method in turn calls each registered instance beforeCompletion method.
        Specified by:
        beforeCompletion in interface jakarta.transaction.Synchronization

      • afterCompletion

        public void afterCompletion​(int status)
        This method will be called during transaction completion. No resource access is allowed. This method in turn calls each registered instance afterCompletion method. After this method completes, instances must register again in the new transaction, but the synchronization manager remains bound to the persistence manager transaction instance.
        Specified by:
        afterCompletion in interface jakarta.transaction.Synchronization
        Parameters:
        status - the completion status of the transaction

      • registerSynchronization

        protected void registerSynchronization​(jakarta.transaction.Synchronization instance)
        Register an instance with this synchronization manager. Note that this is not thread-safe. If multiple threads call this method at the same time, the synchronizations List might become corrupt. The correct way to fix this is to ask the PersistenceManager for the Multithreaded flag and perform a synchronized add if the flag is true. We currently do not have the Multithreaded flag implemented.
        Parameters:
        instance - the instance to be registered