/* * Copyright (C) 2014 The Android Open Source Project * Copyright (c) 1996, 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 java.sql; import dalvik.system.VMStack; import java.util.Iterator; import java.util.ServiceLoader; import java.security.AccessController; import java.security.PrivilegedAction; import java.util.concurrent.CopyOnWriteArrayList; import sun.reflect.CallerSensitive; /** *

The basic service for managing a set of JDBC drivers.
* NOTE: The {@code DataSource} interface, new in the * JDBC 2.0 API, provides another way to connect to a data source. * The use of a DataSource object is the preferred means of * connecting to a data source. * *

As part of its initialization, the DriverManager class will * attempt to load the driver classes referenced in the "jdbc.drivers" * system property. This allows a user to customize the JDBC Drivers * used by their applications. For example in your * ~/.hotjava/properties file you might specify: * 

 * jdbc.drivers=foo.bah.Driver:wombat.sql.Driver:bad.taste.ourDriver
 *
*

The DriverManager methods getConnection and * getDrivers have been enhanced to support the Java Standard Edition * Service Provider mechanism. JDBC 4.0 Drivers must * include the file META-INF/services/java.sql.Driver. This file contains the name of the JDBC drivers * implementation of java.sql.Driver. For example, to load the my.sql.Driver class, * the META-INF/services/java.sql.Driver file would contain the entry: * 

 * my.sql.Driver
 *
* *

Applications no longer need to explictly load JDBC drivers using Class.forName(). Existing programs * which currently load JDBC drivers using Class.forName() will continue to work without * modification. * *

When the method getConnection is called, * the DriverManager will attempt to * locate a suitable driver from amongst those loaded at * initialization and those loaded explicitly using the same classloader * as the current applet or application. * *

* Starting with the Java 2 SDK, Standard Edition, version 1.3, a * logging stream can be set only if the proper * permission has been granted. Normally this will be done with * the tool PolicyTool, which can be used to grant permission * java.sql.SQLPermission "setLog". * @see Driver * @see Connection */ // Android-changed line 2 of the javadoc to "{@code DataSource}" public class DriverManager { // List of registered JDBC drivers private final static CopyOnWriteArrayList registeredDrivers = new CopyOnWriteArrayList(); private static volatile int loginTimeout = 0; private static volatile java.io.PrintWriter logWriter = null; private static volatile java.io.PrintStream logStream = null; // Used in println() to synchronize logWriter private final static Object logSync = new Object(); /* Prevent the DriverManager class from being instantiated. */ private DriverManager(){} /** * Load the initial JDBC drivers by checking the System property * jdbc.properties and then use the {@code ServiceLoader} mechanism */ static { loadInitialDrivers(); println("JDBC DriverManager initialized"); } /** * The SQLPermission constant that allows the * setting of the logging stream. * @since 1.3 */ final static SQLPermission SET_LOG_PERMISSION = new SQLPermission("setLog"); //--------------------------JDBC 2.0----------------------------- /** * Retrieves the log writer. * * The getLogWriter and setLogWriter * methods should be used instead * of the get/setlogStream methods, which are deprecated. * @return a java.io.PrintWriter object * @see #setLogWriter * @since 1.2 */ public static java.io.PrintWriter getLogWriter() { return logWriter; } /** * Sets the logging/tracing PrintWriter object * that is used by the DriverManager and all drivers. *

* There is a minor versioning problem created by the introduction * of the method setLogWriter. The * method setLogWriter cannot create a PrintStream object * that will be returned by getLogStream---the Java platform does * not provide a backward conversion. As a result, a new application * that uses setLogWriter and also uses a JDBC 1.0 driver that uses * getLogStream will likely not see debugging information written * by that driver. *

* Starting with the Java 2 SDK, Standard Edition, version 1.3 release, this method checks * to see that there is an SQLPermission object before setting * the logging stream. If a SecurityManager exists and its * checkPermission method denies setting the log writer, this * method throws a java.lang.SecurityException. * * @param out the new logging/tracing PrintStream object; * null to disable logging and tracing * @throws SecurityException * if a security manager exists and its * checkPermission method denies * setting the log writer * * @see SecurityManager#checkPermission * @see #getLogWriter * @since 1.2 */ public static void setLogWriter(java.io.PrintWriter out) { SecurityManager sec = System.getSecurityManager(); if (sec != null) { sec.checkPermission(SET_LOG_PERMISSION); } logStream = null; logWriter = out; } //--------------------------------------------------------------- /** * Attempts to establish a connection to the given database URL. * The DriverManager attempts to select an appropriate driver from * the set of registered JDBC drivers. * * @param url a database url of the form * jdbc:subprotocol:subname * @param info a list of arbitrary string tag/value pairs as * connection arguments; normally at least a "user" and * "password" property should be included * @return a Connection to the URL * @exception SQLException if a database access error occurs */ @CallerSensitive public static Connection getConnection(String url, java.util.Properties info) throws SQLException { return (getConnection(url, info, VMStack.getCallingClassLoader())); } /** * Attempts to establish a connection to the given database URL. * The DriverManager attempts to select an appropriate driver from * the set of registered JDBC drivers. * * @param url a database url of the form * jdbc:subprotocol:subname * @param user the database user on whose behalf the connection is being * made * @param password the user's password * @return a connection to the URL * @exception SQLException if a database access error occurs */ @CallerSensitive public static Connection getConnection(String url, String user, String password) throws SQLException { java.util.Properties info = new java.util.Properties(); if (user != null) { info.put("user", user); } if (password != null) { info.put("password", password); } return (getConnection(url, info, VMStack.getCallingClassLoader())); } /** * Attempts to establish a connection to the given database URL. * The DriverManager attempts to select an appropriate driver from * the set of registered JDBC drivers. * * @param url a database url of the form * jdbc:subprotocol:subname * @return a connection to the URL * @exception SQLException if a database access error occurs */ @CallerSensitive public static Connection getConnection(String url) throws SQLException { java.util.Properties info = new java.util.Properties(); return (getConnection(url, info, VMStack.getCallingClassLoader())); } /** * Attempts to locate a driver that understands the given URL. * The DriverManager attempts to select an appropriate driver from * the set of registered JDBC drivers. * * @param url a database URL of the form * jdbc:subprotocol:subname * @return a Driver object representing a driver * that can connect to the given URL * @exception SQLException if a database access error occurs */ @CallerSensitive public static Driver getDriver(String url) throws SQLException { println("DriverManager.getDriver(\"" + url + "\")"); ClassLoader callerClassLoader = VMStack.getCallingClassLoader(); // Walk through the loaded registeredDrivers attempting to locate someone // who understands the given URL. for (DriverInfo aDriver : registeredDrivers) { // If the caller does not have permission to load the driver then // skip it. if(isDriverAllowed(aDriver.driver, callerClassLoader)) { try { if(aDriver.driver.acceptsURL(url)) { // Success! println("getDriver returning " + aDriver.driver.getClass().getName()); return (aDriver.driver); } } catch(SQLException sqe) { // Drop through and try the next driver. } } else { println(" skipping: " + aDriver.driver.getClass().getName()); } } println("getDriver: no suitable driver"); throw new SQLException("No suitable driver", "08001"); } /** * Registers the given driver with the DriverManager. * A newly-loaded driver class should call * the method registerDriver to make itself * known to the DriverManager. * * @param driver the new JDBC Driver that is to be registered with the * DriverManager * @exception SQLException if a database access error occurs */ public static synchronized void registerDriver(java.sql.Driver driver) throws SQLException { /* Register the driver if it has not already been added to our list */ if(driver != null) { registeredDrivers.addIfAbsent(new DriverInfo(driver)); } else { // This is for compatibility with the original DriverManager throw new NullPointerException(); } println("registerDriver: " + driver); } /** * Drops a driver from the DriverManager's list. * Applets can only deregister drivers from their own classloaders. * * @param driver the JDBC Driver to drop * @exception SQLException if a database access error occurs */ @CallerSensitive public static synchronized void deregisterDriver(Driver driver) throws SQLException { if (driver == null) { return; } println("DriverManager.deregisterDriver: " + driver); DriverInfo aDriver = new DriverInfo(driver); if(registeredDrivers.contains(aDriver)) { if (isDriverAllowed(driver, VMStack.getCallingClassLoader())) { registeredDrivers.remove(aDriver); } else { // If the caller does not have permission to load the driver then // throw a SecurityException. throw new SecurityException(); } } else { println(" couldn't find driver to unload"); } } /** * Retrieves an Enumeration with all of the currently loaded JDBC drivers * to which the current caller has access. * *

Note: The classname of a driver can be found using * d.getClass().getName() * * @return the list of JDBC Drivers loaded by the caller's class loader */ @CallerSensitive public static java.util.Enumeration getDrivers() { java.util.Vector result = new java.util.Vector(); ClassLoader callerClassLoader = VMStack.getCallingClassLoader(); // Walk through the loaded registeredDrivers. for(DriverInfo aDriver : registeredDrivers) { // If the caller does not have permission to load the driver then // skip it. if(isDriverAllowed(aDriver.driver, callerClassLoader)) { result.addElement(aDriver.driver); } else { println(" skipping: " + aDriver.getClass().getName()); } } return (result.elements()); } /** * Sets the maximum time in seconds that a driver will wait * while attempting to connect to a database. * * @param seconds the login time limit in seconds; zero means there is no limit * @see #getLoginTimeout */ public static void setLoginTimeout(int seconds) { loginTimeout = seconds; } /** * Gets the maximum time in seconds that a driver can wait * when attempting to log in to a database. * * @return the driver login time limit in seconds * @see #setLoginTimeout */ public static int getLoginTimeout() { return (loginTimeout); } /** * Sets the logging/tracing PrintStream that is used * by the DriverManager * and all drivers. *

* In the Java 2 SDK, Standard Edition, version 1.3 release, this method checks * to see that there is an SQLPermission object before setting * the logging stream. If a SecurityManager exists and its * checkPermission method denies setting the log writer, this * method throws a java.lang.SecurityException. * * @param out the new logging/tracing PrintStream; to disable, set to null * @deprecated Use {@code setLogWriter} instead. * @throws SecurityException if a security manager exists and its * checkPermission method denies setting the log stream * * @see SecurityManager#checkPermission * @see #getLogStream */ @Deprecated // Android-added, also changed deprecation comment to include a reason. public static void setLogStream(java.io.PrintStream out) { SecurityManager sec = System.getSecurityManager(); if (sec != null) { sec.checkPermission(SET_LOG_PERMISSION); } logStream = out; if ( out != null ) logWriter = new java.io.PrintWriter(out); else logWriter = null; } /** * Retrieves the logging/tracing PrintStream that is used by the DriverManager * and all drivers. * * @return the logging/tracing PrintStream; if disabled, is null * @deprecated Use {@code getLogWriter} instead. * @see #setLogStream */ @Deprecated // Android-added, also changed deprecation comment to include a reason. public static java.io.PrintStream getLogStream() { return logStream; } /** * Prints a message to the current JDBC log stream. * * @param message a log or tracing message */ public static void println(String message) { synchronized (logSync) { if (logWriter != null) { logWriter.println(message); // automatic flushing is never enabled, so we must do it ourselves logWriter.flush(); } } } //------------------------------------------------------------------------ private static boolean isDriverAllowed(Driver driver, ClassLoader classLoader) { boolean result = false; if(driver != null) { Class aClass = null; try { aClass = Class.forName(driver.getClass().getName(), true, classLoader); } catch (Exception ex) { result = false; } result = ( aClass == driver.getClass() ) ? true : false; } return result; } private static void loadInitialDrivers() { String drivers; try { drivers = AccessController.doPrivileged(new PrivilegedAction() { public String run() { return System.getProperty("jdbc.drivers"); } }); } catch (Exception ex) { drivers = null; } // If the driver is packaged as a Service Provider, load it. // Get all the drivers through the classloader // exposed as a java.sql.Driver.class service. // ServiceLoader.load() replaces the sun.misc.Providers() AccessController.doPrivileged(new PrivilegedAction() { public Void run() { ServiceLoader loadedDrivers = ServiceLoader.load(Driver.class); Iterator driversIterator = loadedDrivers.iterator(); /* Load these drivers, so that they can be instantiated. * It may be the case that the driver class may not be there * i.e. there may be a packaged driver with the service class * as implementation of java.sql.Driver but the actual class * may be missing. In that case a java.util.ServiceConfigurationError * will be thrown at runtime by the VM trying to locate * and load the service. * * Adding a try catch block to catch those runtime errors * if driver not available in classpath but it's * packaged as service and that service is there in classpath. */ try{ while(driversIterator.hasNext()) { driversIterator.next(); } } catch(Throwable t) { // Do nothing } return null; } }); println("DriverManager.initialize: jdbc.drivers = " + drivers); if (drivers == null || drivers.equals("")) { return; } String[] driversList = drivers.split(":"); println("number of Drivers:" + driversList.length); for (String aDriver : driversList) { try { println("DriverManager.Initialize: loading " + aDriver); Class.forName(aDriver, true, ClassLoader.getSystemClassLoader()); } catch (Exception ex) { println("DriverManager.Initialize: load failed: " + ex); } } } // Worker method called by the public getConnection() methods. private static Connection getConnection( String url, java.util.Properties info, ClassLoader callerCL) throws SQLException { /* * When callerCl is null, we should check the application's * (which is invoking this class indirectly) * classloader, so that the JDBC driver class outside rt.jar * can be loaded from here. */ synchronized (DriverManager.class) { // synchronize loading of the correct classloader. if (callerCL == null) { callerCL = Thread.currentThread().getContextClassLoader(); } } if(url == null) { throw new SQLException("The url cannot be null", "08001"); } println("DriverManager.getConnection(\"" + url + "\")"); // Walk through the loaded registeredDrivers attempting to make a connection. // Remember the first exception that gets raised so we can reraise it. SQLException reason = null; for(DriverInfo aDriver : registeredDrivers) { // If the caller does not have permission to load the driver then // skip it. if(isDriverAllowed(aDriver.driver, callerCL)) { try { println(" trying " + aDriver.driver.getClass().getName()); Connection con = aDriver.driver.connect(url, info); if (con != null) { // Success! println("getConnection returning " + aDriver.driver.getClass().getName()); return (con); } } catch (SQLException ex) { if (reason == null) { reason = ex; } } } else { println(" skipping: " + aDriver.getClass().getName()); } } // if we got here nobody could connect. if (reason != null) { println("getConnection failed: " + reason); throw reason; } println("getConnection: no suitable driver found for "+ url); throw new SQLException("No suitable driver found for "+ url, "08001"); } } /* * Wrapper class for registered Drivers in order to not expose Driver.equals() * to avoid the capture of the Driver it being compared to as it might not * normally have access. */ class DriverInfo { final Driver driver; DriverInfo(Driver driver) { this.driver = driver; } public boolean equals(Object other) { return (other instanceof DriverInfo) && this.driver == ((DriverInfo) other).driver; } public int hashCode() { return driver.hashCode(); } public String toString() { return ("driver[className=" + driver + "]"); } }