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/*
* 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 java.util.Iterator;
import java.util.ServiceLoader;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.concurrent.CopyOnWriteArrayList;
import sun.reflect.CallerSensitive;
import sun.reflect.Reflection;
// Android-changed line 2 of the javadoc to "{@code DataSource}".
/**
* 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
*/
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, Reflection.getCallerClass()));
}
/**
* 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, Reflection.getCallerClass()));
}
/**
* 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, Reflection.getCallerClass()));
}
/**
* 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 + "\")");
Class callerClass = Reflection.getCallerClass();
// 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, callerClass)) {
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, Reflection.getCallerClass())) {
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();
Class callerClass = Reflection.getCallerClass();
// 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, callerClass)) {
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);
}
// Android-changed: Added reason to @deprecated to improve the documentation.
/**
* 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
*/
// Android-added: @Deprecated annotation from OpenJDK8u121-b13 to fix build warnings.
@Deprecated
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;
}
// Android-changed: Added reason to @deprecated to improve the documentation.
/**
* 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
*/
// Android-added: @Deprecated annotation from OpenJDK8u121-b13 to fix build warnings.
@Deprecated
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();
}
}
}
//------------------------------------------------------------------------
// Indicates whether the class object that would be created if the code calling
// DriverManager is accessible.
private static boolean isDriverAllowed(Driver driver, Class caller) {
ClassLoader callerCL = caller != null ? caller.getClassLoader() : null;
return isDriverAllowed(driver, callerCL);
}
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, Class caller) 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.
*/
ClassLoader callerCL = caller != null ? caller.getClassLoader() : null;
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 + "]");
}
}