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Diffstat (limited to 'libjava/classpath/java/sql/DriverManager.java')
| -rw-r--r-- | libjava/classpath/java/sql/DriverManager.java | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/libjava/classpath/java/sql/DriverManager.java b/libjava/classpath/java/sql/DriverManager.java new file mode 100644 index 0000000..9e252ab --- /dev/null +++ b/libjava/classpath/java/sql/DriverManager.java @@ -0,0 +1,346 @@ +/* DriverManager.java -- Manage JDBC drivers + Copyright (C) 1999, 2000, 2001, 2003, 2004 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., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 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.StringTokenizer; +import java.util.Vector; + +/** + * 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 (arenn@urbanophile.com) + */ +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() + { + } + + /** + * This method returns the log writer being used by all JDBC drivers. + * This method should be used in place of the deprecated + * <code>getLogStream</code> method. + * + * @return The log writer in use by JDBC drivers. + */ + public static PrintWriter getLogWriter() + { + return log_writer; + } + + /** + * This method sets the log writer being used by JDBC drivers. This is a + * system-wide parameter that affects all drivers. Note that since there + * is no way to retrieve a <code>PrintStream</code> from a + * <code>PrintWriter</code>, this method cannot set the log stream in + * use by JDBC. Thus any older drivers may not see this setting. + * + * @param out The new log writer for JDBC. + */ + public static void setLogWriter(PrintWriter out) + { + DriverManager.log_writer = out; + } + +/** + * This method attempts to return a connection to the specified + * JDBC URL string using the specified connection properties. + * + * @param url The JDBC URL string to connect to. + * @param properties The connection properties. + * + * @return A <code>Connection</code> to that URL. + * + * @exception SQLException If an error occurs. + */ + public static Connection getConnection(String url, Properties properties) + throws SQLException + { + Driver d = getDriver(url); + if (d == null) + throw new SQLException("Driver not found for URL: " + url); + + return d.connect(url, properties); + } + + + /** + * This method attempts to return a connection to the specified + * JDBC URL string using the specified username and password. + * + * @param url The JDBC URL string to connect to. + * @param user The username to connect with. + * @param password The password to connect with. + * @return A <code>Connection</code> to that URL. + * @exception SQLException If an error occurs. + */ + public static Connection getConnection(String url, String user, + String password) throws SQLException + { + Properties p = new Properties(); + + if (user != null) + p.setProperty("user", user); + if (password != null) + p.setProperty("password", password); + + return getConnection(url, p); + } + + /** + * This method attempts to return a connection to the specified + * JDBC URL string. + * + * @param url The JDBC URL string to connect to. + * + * @return A <code>Connection</code> to that URL. + * + * @exception SQLException If an error occurs. + */ + public static Connection getConnection(String url) throws SQLException + { + return getConnection(url, new Properties()); + } + + /** + * This method returns a driver that can connect to the specified + * JDBC URL string. This will be selected from among drivers loaded + * at initialization time and those drivers manually loaded by the + * same class loader as the caller. + * + * @param url The JDBC URL string to find a driver for. + * + * @return A <code>Driver</code> that can connect to the specified + * URL. + * + * @exception SQLException If an error occurs, or no suitable driver can be found. + */ + public static Driver getDriver(String url) throws SQLException + { + // FIXME: Limit driver search to the appropriate subset of loaded drivers. + Enumeration e = drivers.elements(); + while(e.hasMoreElements()) + { + Driver d = (Driver)e.nextElement(); + if (d.acceptsURL(url)) + return d; + } + + throw new SQLException("No driver found for " + url); + } + + /** + * This method registers a new driver with the manager. This is normally + * called by the driver itself in a static initializer. + * + * @param driver The new <code>Driver</code> to add. + * + * @exception SQLException If an error occurs. + */ + public static void registerDriver(Driver driver) throws SQLException + { + if (! drivers.contains(driver)) + drivers.addElement(driver); + } + +/** + * This method de-registers a driver from the manager. + * + * @param driver The <code>Driver</code> to unregister. + * + * @exception SQLException If an error occurs. + */ + public static void deregisterDriver(Driver driver) throws SQLException + { + if (drivers.contains(driver)) + drivers.removeElement(driver); + } + + /** + * This method returns a list of all the currently registered JDBC drivers + * that were loaded by the current <code>ClassLoader</code>. + * + * @return An <code>Enumeration</code> of all currently loaded JDBC drivers. + */ + public static Enumeration getDrivers() + { + Vector v = new Vector(); + Enumeration e = drivers.elements(); + + // Is this right? + ClassLoader cl = Thread.currentThread().getContextClassLoader(); + + while(e.hasMoreElements()) + { + Object obj = e.nextElement(); + + ClassLoader loader = obj.getClass().getClassLoader(); + + if (loader == null) + loader = ClassLoader.getSystemClassLoader(); + if (! loader.equals(cl)) + continue; + + v.addElement(obj); + } + + return v.elements(); + } + + /** + * This method set the login timeout used by JDBC drivers. This is a + * system-wide parameter that applies to all drivers. + * + * @param login_timeout The new login timeout value. + */ + public static void setLoginTimeout(int seconds) + { + DriverManager.login_timeout = login_timeout; + } + + /** + * This method returns the login timeout in use by JDBC drivers systemwide. + * + * @return The login timeout. + */ + public static int getLoginTimeout() + { + return login_timeout; + } + + /** + * This method sets the log stream in use by JDBC. + * + * @param log_stream The log stream in use by JDBC. + * + * @deprecated Use <code>setLogWriter</code> instead. + */ + public static void setLogStream(PrintStream out) + { + DriverManager.log_stream = log_stream; + } + + /** + * This method returns the log stream in use by JDBC. + * + * @return The log stream in use by JDBC. + * + * @deprecated Use <code>getLogWriter()</code> instead. + */ + public static PrintStream getLogStream() + { + return log_stream; + } + + /** + * This method prints the specified line to the log stream. + * + * @param str The string to write to the log stream. + */ + public static void println(String message) + { + if (log_stream != null) // Watch for user not using logging + log_stream.println(message); + } +} |