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	/*
	* Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package javax.sql;

	import java.sql.Connection;
	import java.sql.SQLException;

	/**
	* An object that provides hooks for connection pool management.
	* A <code>PooledConnection</code> object
	* represents a physical connection to a data source. The connection
	* can be recycled rather than being closed when an application is
	* finished with it, thus reducing the number of connections that
	* need to be made.
	* <P>
	* An application programmer does not use the <code>PooledConnection</code>
	* interface directly; rather, it is used by a middle tier infrastructure
	* that manages the pooling of connections.
	* <P>
	* When an application calls the method <code>DataSource.getConnection</code>,
	* it gets back a <code>Connection</code> object. If connection pooling is
	* being done, that <code>Connection</code> object is actually a handle to
	* a <code>PooledConnection</code> object, which is a physical connection.
	* <P>
	* The connection pool manager, typically the application server, maintains
	* a pool of <code>PooledConnection</code> objects. If there is a
	* <code>PooledConnection</code> object available in the pool, the
	* connection pool manager returns a <code>Connection</code> object that
	* is a handle to that physical connection.
	* If no <code>PooledConnection</code> object is available, the
	* connection pool manager calls the <code>ConnectionPoolDataSource</code>
	* method <code>getPoolConnection</code> to create a new physical connection. The
	* JDBC driver implementing <code>ConnectionPoolDataSource</code> creates a
	* new <code>PooledConnection</code> object and returns a handle to it.
	* <P>
	* When an application closes a connection, it calls the <code>Connection</code>
	* method <code>close</code>. When connection pooling is being done,
	* the connection pool manager is notified because it has registered itself as
	* a <code>ConnectionEventListener</code> object using the
	* <code>ConnectionPool</code> method <code>addConnectionEventListener</code>.
	* The connection pool manager deactivates the handle to
	* the <code>PooledConnection</code> object and returns the
	* <code>PooledConnection</code> object to the pool of connections so that
	* it can be used again. Thus, when an application closes its connection,
	* the underlying physical connection is recycled rather than being closed.
	* <P>
	* The physical connection is not closed until the connection pool manager
	* calls the <code>PooledConnection</code> method <code>close</code>.
	* This method is generally called to have an orderly shutdown of the server or
	* if a fatal error has made the connection unusable.
	*
	* <p>
	* A connection pool manager is often also a statement pool manager, maintaining
	* a pool of <code>PreparedStatement</code> objects.
	* When an application closes a prepared statement, it calls the
	* <code>PreparedStatement</code>
	* method <code>close</code>. When <code>Statement</code> pooling is being done,
	* the pool manager is notified because it has registered itself as
	* a <code>StatementEventListener</code> object using the
	* <code>ConnectionPool</code> method <code>addStatementEventListener</code>.
	* Thus, when an application closes its <code>PreparedStatement</code>,
	* the underlying prepared statement is recycled rather than being closed.
	* <P>
	*
	* @since 1.4
	*/

	public interface PooledConnection {

	/**
	* Creates and returns a <code>Connection</code> object that is a handle
	* for the physical connection that
	* this <code>PooledConnection</code> object represents.
	* The connection pool manager calls this method when an application has
	* called the method <code>DataSource.getConnection</code> and there are
	* no <code>PooledConnection</code> objects available. See the
	* {@link PooledConnection interface description} for more information.
	*
	* @return a <code>Connection</code> object that is a handle to
	* this <code>PooledConnection</code> object
	* @exception SQLException if a database access error occurs
	* @exception java.sql.SQLFeatureNotSupportedException if the JDBC driver does not support
	* this method
	* @since 1.4
	*/
	Connection getConnection() throws SQLException;

	/**
	* Closes the physical connection that this <code>PooledConnection</code>
	* object represents. An application never calls this method directly;
	* it is called by the connection pool module, or manager.
	* <P>
	* See the {@link PooledConnection interface description} for more
	* information.
	*
	* @exception SQLException if a database access error occurs
	* @exception java.sql.SQLFeatureNotSupportedException if the JDBC driver does not support
	* this method
	* @since 1.4
	*/
	void close() throws SQLException;

	/**
	* Registers the given event listener so that it will be notified
	* when an event occurs on this <code>PooledConnection</code> object.
	*
	* @param listener a component, usually the connection pool manager,
	* that has implemented the
	* <code>ConnectionEventListener</code> interface and wants to be
	* notified when the connection is closed or has an error
	* @see #removeConnectionEventListener
	*/
	void addConnectionEventListener(ConnectionEventListener listener);

	/**
	* Removes the given event listener from the list of components that
	* will be notified when an event occurs on this
	* <code>PooledConnection</code> object.
	*
	* @param listener a component, usually the connection pool manager,
	* that has implemented the
	* <code>ConnectionEventListener</code> interface and
	* been registered with this <code>PooledConnection</code> object as
	* a listener
	* @see #addConnectionEventListener
	*/
	void removeConnectionEventListener(ConnectionEventListener listener);

	/**
	* Registers a <code>StatementEventListener</code> with this <code>PooledConnection</code> object. Components that
	* wish to be notified when <code>PreparedStatement</code>s created by the
	* connection are closed or are detected to be invalid may use this method
	* to register a <code>StatementEventListener</code> with this <code>PooledConnection</code> object.
	* <p>
	* @param listener an component which implements the <code>StatementEventListener</code>
	* interface that is to be registered with this <code>PooledConnection</code> object
	* <p>
	* @since 1.6
	*/
	public void addStatementEventListener(StatementEventListener listener);

	/**
	* Removes the specified <code>StatementEventListener</code> from the list of
	* components that will be notified when the driver detects that a
	* <code>PreparedStatement</code> has been closed or is invalid.
	* <p>
	* @param listener the component which implements the
	* <code>StatementEventListener</code> interface that was previously
	* registered with this <code>PooledConnection</code> object
	* <p>
	* @since 1.6
	*/
	public void removeStatementEventListener(StatementEventListener listener);

	}

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