org.eclipse.persistence.internal.databaseaccess.Accessor Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of eclipselink Show documentation
Show all versions of eclipselink Show documentation
EclipseLink build based upon Git transaction f2b9fc5
/*
* Copyright (c) 1998, 2022 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0,
* or the Eclipse Distribution License v. 1.0 which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
*/
// Contributors:
// Oracle - initial API and implementation from Oracle TopLink
package org.eclipse.persistence.internal.databaseaccess;
import java.util.Vector;
import org.eclipse.persistence.exceptions.DatabaseException;
import org.eclipse.persistence.internal.sequencing.SequencingCallback;
import org.eclipse.persistence.internal.sequencing.SequencingCallbackFactory;
import org.eclipse.persistence.internal.sessions.AbstractRecord;
import org.eclipse.persistence.internal.sessions.AbstractSession;
import org.eclipse.persistence.queries.Call;
import org.eclipse.persistence.sessions.Login;
import org.eclipse.persistence.sessions.server.ConnectionPool;
/**
* INTERNAL:
* Accessor defines the interface used primarily by the assorted
* TopLink Sessions to interact with a data store. In "normal"
* TopLink this data store is a relational database. But this interface
* also allows developers using the TopLink SDK to develop Accessors
* to other, non-relational, data stores.
*
* Accessors must implement the following behavior:
* - connect to and disconnect from the data store
*
- handle transaction contexts
*
- execute calls that read, insert, update, and delete data
*
- keep track of concurrently executing calls
*
- supply metadata about the data store
*
*
* @see org.eclipse.persistence.internal.sessions.AbstractSession
* @see Call
*
* @author Big Country
* @since TOPLink/Java 3.0
*/
public interface Accessor extends Cloneable {
/**
* 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.
*/
void closeJTSConnection();
/**
* Begin a transaction on the data store.
*/
void beginTransaction(AbstractSession session) throws DatabaseException;
/**
* Return a clone of the accessor.
*/
Object clone();
/**
* 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.
*/
void closeConnection();
/**
* Commit a transaction on the data store.
*/
void commitTransaction(AbstractSession session) throws DatabaseException;
/**
* Connect to the data store using the configuration
* information in the login.
*/
void connect(Login login, AbstractSession session) throws DatabaseException;
/**
* Decrement the number of calls in progress.
* Used for external pooling.
*/
void decrementCallCount();
/**
* Disconnect from the data store.
*/
void disconnect(AbstractSession session) throws DatabaseException;
/**
* Execute the call.
* The actual behavior of the execution depends on the type of call.
* The call may be parameterized where the arguments are in the translation row.
* The row will be empty if there are no parameters.
* @return a row, a collection of rows, a row count, or a cursor
*/
Object executeCall(Call call, AbstractRecord translationRow, AbstractSession session) throws DatabaseException;
/**
* Execute any deferred select calls. This method will generally be called
* after one or more select calls have been collected in a LOBValueWriter (to be
* executed after all insert calls are executed).
* Bug 2804663.
*
* @see org.eclipse.persistence.internal.helper.LOBValueWriter#buildAndExecuteSelectCalls(AbstractSession)
*/
void flushSelectCalls(AbstractSession session);
/**
* Return the number of calls currently in progress.
* Used for load balancing and external pooling.
*/
int getCallCount();
/**
* Return the column metadata for the specified
* selection criteria.
*/
Vector getColumnInfo(String catalog, String schema, String tableName, String columnName, AbstractSession session) throws DatabaseException;
/**
* Return the column metadata for the specified
* selection criteria limited to the context of the current {@code Accessor}.
*/
Vector getColumnInfo(String tableName, String columnName, AbstractSession session) throws DatabaseException;
/**
* Return the JDBC connection for relational accessors.
* This will fail for non-relational accessors.
*/
java.sql.Connection getConnection();
/**
* Return the driver level connection,
* this will need to be cast to the implementation class for the data access type being used.
*/
Object getDatasourceConnection();
/**
* Return sequencing callback.
*/
SequencingCallback getSequencingCallback(SequencingCallbackFactory sequencingCallbackFactory);
/**
* Return the table metadata for the specified
* selection criteria.
*/
Vector getTableInfo(String catalog, String schema, String tableName, String[] types, AbstractSession session) throws DatabaseException;
/**
* Return the table metadata for the specified
* selection criteria limited to the context of the current {@code Accessor}.
*/
Vector getTableInfo(String tableName, String[] types, AbstractSession session) throws DatabaseException;
/**
* Increment the number of calls in progress.
* Used for external pooling.
*/
void incrementCallCount(AbstractSession session);
/**
* Return whether the accessor is connected to the data store.
*/
boolean isConnected();
/**
* Return whether the accessor is in transaction.
*/
boolean isInTransaction();
/**
* 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.
*/
boolean isValid();
/**
* Reconnect to the database. This can be used if the connection was
* temporarily disconnected or if it timed out.
*/
void reestablishConnection(AbstractSession session) throws DatabaseException;
/**
* Roll back a transaction on the data store.
*/
void rollbackTransaction(AbstractSession session) throws DatabaseException;
/**
* This should be set to false if a communication failure occurred durring a call execution.
* In the case of an invalid accessor the Accessor will not be returned to the pool.
*/
void setIsValid(boolean isValid);
/**
* Return whether the accessor uses an external
* transaction controller (e.g. JTS).
*/
boolean usesExternalTransactionController();
/**
* Return whether the accessor uses external connection pooling.
*/
boolean usesExternalConnectionPooling();
/**
* 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
*/
void writesCompleted(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.
*/
void createCustomizer(AbstractSession session);
/**
* 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.
*/
void releaseCustomizer();
/**
* 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.
*/
void releaseCustomizer(AbstractSession session);
/**
* Reset the accessor before being released.
*/
void reset();
/**
* Return the associated connection pool this connection was obtained from.
*/
ConnectionPool getPool();
/**
* Set the associated connection pool this connection was obtained from.
*/
void setPool(ConnectionPool pool);
}