source: trunk/src/gcc/libjava/java/sql/DriverManager.java@ 2171

/* DriverManager.java -- Manage JDBC drivers
   Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
 
GNU Classpath 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 for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module.  An independent module is a module which is not derived from
or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so.  If you do not wish to do so, delete this
exception statement from your version. */

package java.sql;

import java.io.PrintStream;
import java.io.PrintWriter;
import java.util.Enumeration;
import java.util.Properties;
import java.util.Vector;
import java.util.StringTokenizer;

/**
  * This class manages the JDBC drivers in the system. It maintains a
  * registry of drivers and locates the appropriate driver to handle a
  * JDBC database URL.
  * <p>
  * On startup, <code>DriverManager</code> loads all the managers specified
  * by the system property <code>jdbc.drivers</code>.  The value of this
  * property should be a colon separated list of fully qualified driver
  * class names.  Additional drivers can be loaded at any time by
  * simply loading the driver class with <code>class.forName(String)</code>.
  * The driver should automatically register itself in a static 
  * initializer.
  * <p>
  * The methods in this class are all <code>static</code>. This class
  * cannot be instantiated.
  *
  * @author Aaron M. Renn ([email protected])
  */
public class DriverManager 
{
  /**
   * This is the log stream for JDBC drivers.
   */
  private static PrintStream log_stream;

  /**
   * This is the log writer for JDBC drivers.
   */
  private static PrintWriter log_writer;

  /**
   * This is the login timeout used by JDBC drivers.
   */
  private static int login_timeout;

  /**
   * This is the list of JDBC drivers that are loaded.
   */
  private static Vector drivers;
   // Hmm, seems like we might want to do a Hashtable and lookup by something,
   // but what would it be?

  // Load all drivers on startup
  static
  {
    drivers = new Vector();

    String driver_string = System.getProperty("jdbc.drivers");
    if (driver_string != null)
      {
        StringTokenizer st = new StringTokenizer(driver_string);
        while (st.hasMoreTokens())
          {
            String driver_classname = st.nextToken();

            try
              {
                Class.forName(driver_classname); // The driver registers itself
              }
            catch (Exception e) { ; } // Ignore not founds
          }
      }

  }

  /** Can't be instantiated. */
  private DriverManager()
  {
  }