/*************************************************************************
/* Driver.java -- A JDBC driver
/*
/* Copyright (c) 1999 Free Software Foundation, Inc.
/* Written by Aaron M. Renn (arenn@urbanophile.com)
/*
/* This library is free software; you can redistribute it and/or modify
/* it under the terms of the GNU Library General Public License as published 
/* by the Free Software Foundation, either version 2 of the License, or
/* (at your option) any later verion.
/*
/* This library 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 Library General Public License for more details.
/*
/* You should have received a copy of the GNU Library General Public License
/* along with this library; if not, write to the Free Software Foundation
/* Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307 USA
/*************************************************************************/

package java.sql;

import java.util.Properties;

/**
  * This interface specifies a mechanism for accessing a JDBC database
  * driver.  When the class implementing this method is loaded, it should
  * register an instance of itself with the <code>DriverManager</code> in
  * a static initializer.  
  * <p>
  * Because the <code>DriverManager</code> might attempt to use several
  * drivers to find one that can connect to the requested database, 
  * this driver should not cause large numbers of classes and code to
  * be loaded.  If another driver is the one that ends up performing the
  * request, any loading done by this driver would be wasted.
  *
  * @author Aaron M. Renn (arenn@urbanophile.com)
  */
public abstract interface Driver
{

/**
  * This method returns the major version number of the driver.
  *
  * @return The major version number of the driver.
  */
public abstract int
getMajorVersionNumber();

/*************************************************************************/

/**
  * This method returns the minor version number of the driver.
  *
  * @return The minor version number of the driver.
  */
public abstract int
getMinorVersion();

/*************************************************************************/

/**
  * This method tests whether or not the driver is JDBC compliant.  This
  * method should only return <code>true</code> if the driver has been
  * certified as JDBC compliant.
  *
  * @return <code>true</code> if the driver has been certified JDBC compliant,
  * <code>false</code> otherwise.
  */
public abstract boolean
jdbcCompliant();

/*************************************************************************/

/**
  * This method returns an array of possible properties that could be
  * used to connect to the specified database.
  *
  * @param url The URL string of the database to connect to.
  * @param properties The list of properties the caller is planning to use
  * to connect to the database.
  *
  * @return A list of possible additional properties for a connection to this
  * database.  This list may be empty.
  *
  * @exception SQLException If an error occurs.
  */
public abstract DriverPropertyInfo[]
getPropertyInfo(String url, Properties properties) throws SQLException;

/*************************************************************************/

/**
  * This method tests whether or not the driver believes it can connect to
  * the specified database.  The driver should only test whether it 
  * understands and accepts the URL. It should not necessarily attempt to 
  * probe the database for a connection.
  *
  * @param The database URL string.
  *
  * @return <code>true</code> if the drivers can connect to the database, 
  * <code>false</code> otherwise.
  *
  * @exception SQLException If an error occurs.
  */
public abstract boolean
acceptsURL(String url) throws SQLException;

/*************************************************************************/

/**
  * This method connects to the specified database using the connection
  * properties supplied.  If the driver does not understand the database
  * URL, it should return <code>null</code> instead of throwing an
  * exception since the <code>DriverManager</code> will probe a driver
  * in this manner.
  * 
  * @param url The URL string for this connection.
  * @param properties The list of database connection properties.
  *
  * @return A <code>Connection</code> object for the newly established
  * connection, or <code>null</code> if the URL is not understood.
  *
  * @exception SQLException If an error occurs.
  */
public abstract Connection
connect(String url, Properties properties) throws SQLException;

} // interface Driver