Module org.eclipse.persistence.core
Package org.eclipse.persistence.internal.databaseaccess

Class DatasourceAccessor

  • All Implemented Interfaces:
    Cloneable, Accessor
    Direct Known Subclasses:
    DatabaseAccessor, EISAccessor, XMLAccessor
    public abstract class DatasourceAccessor
extends Object
implements Accessor
    INTERNAL: DatasourceAccessor is an abstract implementation of the Accessor interface providing common functionality to the concrete database and EIS accessors. It is responsible for connecting, transactions, call execution
    Since:
    OracleAS TopLink 10g (10.0.3) 05/28/2008-1.0M8 Andrei Ilitchev. - 224964: Provide support for Proxy Authentication through JPA. Added ConnectionCustomizer, also fixed postConnect/preDisconnect ExternalConnection calls so that they called in case of reads, too.
    Author:
    James
    See Also:
    Call, Login

    • Field Detail

      • datasourceConnection

        protected Object datasourceConnection
        Store the reference to the driver level connection.

      • login

        protected Login login
        Store the login information that connected this accessor.

      • callCount

        protected int callCount
        Keep track of the number of concurrent active calls. This is used for connection pooling for loadbalancing and for external connection pooling.

      • storedProcedureStatementsCount

        public int storedProcedureStatementsCount
        Keep track of the number of the storedprocedure statement that being executed.

      • readStatementsCount

        public int readStatementsCount
        Keep track of the number of the read statement that being executed.

      • writeStatementsCount

        public int writeStatementsCount
        Keep track of the number of the write statement that being executed.

      • STOREDPROCEDURE_STATEMENTS_COUNT_PROPERTY

        public static final String STOREDPROCEDURE_STATEMENTS_COUNT_PROPERTY
        See Also:
        Constant Field Values

      • isInTransaction

        protected boolean isInTransaction
        Keep track if the accessor is within a transaction context

      • isConnected

        protected boolean isConnected
        Keep track of whether the accessor is "connected".

      • platform

        protected DatasourcePlatform platform
        This is also required to ensure all accessors for a session are using the same platform.

      • isValid

        protected boolean isValid
        This attribute is used to determine if the connection should be returned to the pool or removed from the pool and closed. It will be set to false if an exception occurs during Call execution.

      • sequencingCallback

        protected transient SequencingCallback sequencingCallback
        During (not external) transaction, SequencingManager may set SequencingCallback on the accessor, The callback's only method is called when transaction commits, after transaction is completed the callback is discarded.

      • possibleFailure

        protected boolean possibleFailure
        This attribute is used to track failures on an accessor that may be communication based. If a failure is detected executing a call with a query timeout this flag is set. If an error happens twice in a row on the same accessor then that accessor will be checked for a comm error. If there is no query timeout then the flag is not set and the accessor will be checked immediately.

      • currentSession

        protected transient AbstractSession currentSession
        Used only in externalConnectionPooling case. Indicates which session is currently using connection. Allows to rise appropriate session's event when connection is already/still alive. Events will be risen when ClientSession or DatabaseSession acquires connection in the beginning and releases connection in the end of transaction (in afterCompletion in jta case). In case the session requires exclusive connection (ExclusiveIsolatedClientSession) the events will be risen every time the session acquires or releases connection - which is a rare event - the connection is kept for the duration of jta transaction, after jta transaction is completed the new connection is acquired on a first query execution and kept until the next beginTransaction call. In non-jta case the connection is acquired for session's life and release only by session's release. Note that the attribute is nullified only in one place - by closeConnection method.

      • usesExternalConnectionPooling

        protected boolean usesExternalConnectionPooling
        PERF: Cache connection pooling flag.

      • shouldCheckConnection

        public static boolean shouldCheckConnection
        Back-door to allow isConnect checks. Since we now support fail-over and retry, removing old isConnected usage which can cause major performance issues (on Sybase), and minor ones in general.

      • customizer

        protected ConnectionCustomizer customizer
        Allows session-specific connection customization.

    • Constructor Detail

      • DatasourceAccessor

        protected DatasourceAccessor()
        Default Constructor.

    • Method Detail

      • closeJTSConnection

        public void closeJTSConnection()
        Called from beforeCompletion external transaction synchronization listener callback to close the external connection corresponding to the completing external transaction. Final sql calls could be sent through the connection by this method before it closes the connection.
        Specified by:
        closeJTSConnection in interface Accessor

      • setIsInTransaction

        protected void setIsInTransaction​(boolean value)
        Set the transaction transaction status of the receiver.

      • setIsValid

        public void setIsValid​(boolean isValid)
        This should be set to false if a communication failure occurred during a call execution. In the case of an invalid accessor the Accessor will not be returned to the pool.
        Specified by:
        setIsValid in interface Accessor

      • isInTransaction

        public boolean isInTransaction()
        Return the transaction status of the receiver.
        Specified by:
        isInTransaction in interface Accessor

      • isValid

        public boolean isValid()
        Returns true if this Accessor can continue to be used. This will be false if a communication failure occurred during a call execution. In the case of an invalid accessor the Accessor will not be returned to the pool.
        Specified by:
        isValid in interface Accessor

      • isPossibleFailure

        public boolean isPossibleFailure()

      • setPossibleFailure

        public void setPossibleFailure​(boolean possibleFailure)

      • usesExternalConnectionPooling

        public boolean usesExternalConnectionPooling()
        Return true if some external connection pool is in use.
        Specified by:
        usesExternalConnectionPooling in interface Accessor

      • basicBeginTransaction

        protected abstract void basicBeginTransaction​(AbstractSession session)
        Begin the driver level transaction.

      • basicCommitTransaction

        protected abstract void basicCommitTransaction​(AbstractSession session)
        Commit the driver level transaction.

      • basicRollbackTransaction

        protected abstract void basicRollbackTransaction​(AbstractSession session)
        Rollback the driver level transaction.

      • decrementCallCount

        public void decrementCallCount()
        Used for load balancing and external pooling.
        Specified by:
        decrementCallCount in interface Accessor

      • reset

        public void reset()
        Reset statement count.
        Specified by:
        reset in interface Accessor

      • setIsConnected

        protected void setIsConnected​(boolean isConnected)
        Set whether the accessor has a connection to the "data store".

      • setCallCount

        protected void setCallCount​(int callCount)
        Used for load balancing and external pooling.

      • getCallCount

        public int getCallCount()
        Used for load balancing and external pooling.
        Specified by:
        getCallCount in interface Accessor

      • closeDatasourceConnection

        protected abstract void closeDatasourceConnection()
        Close the connection to the driver level datasource.

      • buildConnectLog

        protected abstract void buildConnectLog​(AbstractSession session)
        Build a log string of any driver metadata that can be obtained.

      • getLogin

        public Login getLogin()
        Return the login

      • setLogin

        protected void setLogin​(Login login)
        SECURE: set the login

      • closeConnection

        public void closeConnection()
        Close the accessor's connection. This is used only for external connection pooling when it is intended for the connection to be reconnected in the future.
        Specified by:
        closeConnection in interface Accessor

      • reestablishConnection

        public void reestablishConnection​(AbstractSession session)
                           throws DatabaseException
        PUBLIC: Reconnect to the database. This can be used if the connection was disconnected or timedout. This ensures that the security is checked as it is public. Because the messages can take a long time to build, pre-check whether messages should be logged.
        Specified by:
        reestablishConnection in interface Accessor
        Throws:
        DatabaseException

      • reconnect

        protected void reconnect​(AbstractSession session)
                  throws DatabaseException
        Attempt to save some of the cost associated with getting a fresh connection. Assume the DatabaseDriver has been cached, if appropriate. Note: Connections that are participating in transactions will not be refreshed.^M
        Throws:
        DatabaseException

      • getDatasourcePlatform

        public DatasourcePlatform getDatasourcePlatform()
        Return the platform.

      • setDatasourcePlatform

        public void setDatasourcePlatform​(DatasourcePlatform platform)
        Set the platform. This should be set to the session's platform, not the connections which may not be configured correctly.

      • getConnection

        public Connection getConnection()
        Helper method to return the JDBC connection for DatabaseAccessor. Was going to deprecate this, but since most clients are JDBC this is useful.
        Specified by:
        getConnection in interface Accessor

      • getReadStatementsCount

        public int getReadStatementsCount()
        Return the number of read statements.

      • getWriteStatementsCount

        public int getWriteStatementsCount()
        Return the number of write statements.

      • getStoredProcedureStatementsCount

        public int getStoredProcedureStatementsCount()
        Return the number of stored procedure call.

      • setDatasourceConnection

        protected void setDatasourceConnection​(Object connection)
        If client requires to manually set connection they can use the connection manager.

      • usesExternalTransactionController

        public boolean usesExternalTransactionController()
        Return true if some external transaction service is controlling transactions.
        Specified by:
        usesExternalTransactionController in interface Accessor

      • isConnected

        public boolean isConnected()
        Return true if the accessor is currently connected to a data source. Return false otherwise.
        Specified by:
        isConnected in interface Accessor

      • isDatasourceConnected

        protected abstract boolean isDatasourceConnected()
        Return if the driver level connection is connected.

      • writesCompleted

        public void writesCompleted​(AbstractSession session)
        This method will be called after a series of writes have been issued to mark where a particular set of writes has completed. It will be called from commitTransaction and may be called from writeChanges. Its main purpose is to ensure that the batched statements have been executed
        Specified by:
        writesCompleted in interface Accessor

      • createCustomizer

        public void createCustomizer​(AbstractSession session)
        Attempts to create ConnectionCustomizer. If created the customizer is cached by the accessor. Called by the owner of accessor (DatabaseSession, ServerSession through ConnectionPool) just once, typically right after the accessor is created. Also called by ClientSession when it acquires write accessor. If accessor already has a customizer set by ConnectionPool then ClientSession's customizer compared with the existing one and if they are not equal (don't produce identical customization) then the new customizer set onto accessor, caching the old customizer so that it could be restored later.
        Specified by:
        createCustomizer in interface Accessor

      • setCustomizer

        protected void setCustomizer​(ConnectionCustomizer newCustomizer)
        Set customizer, customize the connection if it's available.

      • releaseCustomizer

        public void releaseCustomizer()
        Clear customizer if it's active and set it to null. Called by the same object that has created customizer (DatabaseSession, ConnectionPool) when the latter is no longer required, typically before releasing the accessor. Ignored if there's no customizer.
        Specified by:
        releaseCustomizer in interface Accessor

      • releaseCustomizer

        public void releaseCustomizer​(AbstractSession session)
        Clear and remove customizer if its session is the same as the passed one; in case prevCustomizer exists set it as a new customizer. Called when ClientSession releases write accessor: if the customizer was created by the ClientSession it's removed, and the previous customizer (that ConnectionPool had set) is brought back; otherwise the customizer (created by ConnectionPool) is kept. Ignored if there's no customizer.
        Specified by:
        releaseCustomizer in interface Accessor

      • reestablishCustomizer

        protected void reestablishCustomizer()
        This method is called by reestablishConnection. Nothing needs to be done in case customize is not active (customization hasn't been applied yet). to repair existing customizer after connection became invalid. However if connection has been customized then if connection is still there and deemed to be valid - clear customization. Otherwise (or if clear fails) remove customizer and set its prevCustomizer as a new customizer, then re-create customizer using the same session as the original one.

      • getPool

        public ConnectionPool getPool()
        Return the associated connection pool this connection was obtained from.
        Specified by:
        getPool in interface Accessor

      • setPool

        public void setPool​(ConnectionPool pool)
        Set the associated connection pool this connection was obtained from.
        Specified by:
        setPool in interface Accessor