/*
* Copyright (c) 2003, PostgreSQL Global Development Group
* See the LICENSE file in the project root for more information.
*/
package org.postgresql;
import org.postgresql.jdbc.
PgConnection;
import org.postgresql.util.
DriverInfo;
import org.postgresql.util.
ExpressionProperties;
import org.postgresql.util.
GT;
import org.postgresql.util.
HostSpec;
import org.postgresql.util.
PSQLException;
import org.postgresql.util.
PSQLState;
import org.postgresql.util.
SharedTimer;
import org.postgresql.util.
URLCoder;
import org.postgresql.util.
WriterHandler;
import java.io.
IOException;
import java.io.
InputStream;
import java.net.
URL;
import java.security.
AccessController;
import java.security.
PrivilegedActionException;
import java.security.
PrivilegedExceptionAction;
import java.sql.
Connection;
import java.sql.
DriverManager;
import java.sql.
DriverPropertyInfo;
import java.sql.
SQLException;
import java.sql.
SQLFeatureNotSupportedException;
import java.util.
ArrayList;
import java.util.
Enumeration;
import java.util.
Properties;
import java.util.
Set;
import java.util.logging.
Formatter;
import java.util.logging.
Level;
import java.util.logging.
Logger;
import java.util.logging.
SimpleFormatter;
import java.util.logging.
StreamHandler;
/**
* <p>The Java SQL framework allows for multiple database drivers. Each driver should supply a class
* that implements the Driver interface</p>
*
* <p>The DriverManager will try to load as many drivers as it can find and then for any given
* connection request, it will ask each driver in turn to try to connect to the target URL.</p>
*
* <p>It is strongly recommended that each Driver class should be small and standalone so that the
* Driver class can be loaded and queried without bringing in vast quantities of supporting code.</p>
*
* <p>When a Driver class is loaded, it should create an instance of itself and register it with the
* DriverManager. This means that a user can load and register a driver by doing
* Class.forName("foo.bah.Driver")</p>
*
* @see org.postgresql.PGConnection
* @see java.sql.Driver
*/
public class
Driver implements java.sql.
Driver {
private static
Driver registeredDriver;
private static final
Logger PARENT_LOGGER =
Logger.
getLogger("org.postgresql");
private static final
Logger LOGGER =
Logger.
getLogger("org.postgresql.Driver");
private static
SharedTimer sharedTimer = new
SharedTimer();
private static final
String DEFAULT_PORT =
"5432";
static {
try {
// moved the registerDriver from the constructor to here
// because some clients call the driver themselves (I know, as
// my early jdbc work did - and that was based on other examples).
// Placing it here, means that the driver is registered once only.
register();
} catch (
SQLException e) {
throw new
ExceptionInInitializerError(
e);
}
}
// Helper to retrieve default properties from classloader resource
// properties files.
private
Properties defaultProperties;
private synchronized
Properties getDefaultProperties() throws
IOException {
if (
defaultProperties != null) {
return
defaultProperties;
}
// Make sure we load properties with the maximum possible privileges.
try {
defaultProperties =
AccessController.
doPrivileged(new
PrivilegedExceptionAction<
Properties>() {
public
Properties run() throws
IOException {
return
loadDefaultProperties();
}
});
} catch (
PrivilegedActionException e) {
throw (
IOException)
e.
getException();
}
return
defaultProperties;
}
private
Properties loadDefaultProperties() throws
IOException {
Properties merged = new
Properties();
try {
PGProperty.
USER.
set(
merged,
System.
getProperty("user.name"));
} catch (
SecurityException se) {
// We're just trying to set a default, so if we can't
// it's not a big deal.
}
// If we are loaded by the bootstrap classloader, getClassLoader()
// may return null. In that case, try to fall back to the system
// classloader.
//
// We should not need to catch SecurityException here as we are
// accessing either our own classloader, or the system classloader
// when our classloader is null. The ClassLoader javadoc claims
// neither case can throw SecurityException.
ClassLoader cl =
getClass().
getClassLoader();
if (
cl == null) {
LOGGER.
log(
Level.
FINE, "Can't find our classloader for the Driver; "
+ "attempt to use the system class loader");
cl =
ClassLoader.
getSystemClassLoader();
}
if (
cl == null) {
LOGGER.
log(
Level.
WARNING, "Can't find a classloader for the Driver; not loading driver "
+ "configuration from org/postgresql/driverconfig.properties");
return
merged; // Give up on finding defaults.
}
LOGGER.
log(
Level.
FINE, "Loading driver configuration via classloader {0}",
cl);
// When loading the driver config files we don't want settings found
// in later files in the classpath to override settings specified in
// earlier files. To do this we've got to read the returned
// Enumeration into temporary storage.
ArrayList<
URL>
urls = new
ArrayList<
URL>();
Enumeration<
URL>
urlEnum =
cl.
getResources("org/postgresql/driverconfig.properties");
while (
urlEnum.
hasMoreElements()) {
urls.
add(
urlEnum.
nextElement());
}
for (int
i =
urls.
size() - 1;
i >= 0;
i--) {
URL url =
urls.
get(
i);
LOGGER.
log(
Level.
FINE, "Loading driver configuration from: {0}",
url);
InputStream is =
url.
openStream();
merged.
load(
is);
is.
close();
}
return
merged;
}
/**
* <p>Try to make a database connection to the given URL. The driver should return "null" if it
* realizes it is the wrong kind of driver to connect to the given URL. This will be common, as
* when the JDBC driverManager is asked to connect to a given URL, it passes the URL to each
* loaded driver in turn.</p>
*
* <p>The driver should raise an SQLException if it is the right driver to connect to the given URL,
* but has trouble connecting to the database.</p>
*
* <p>The java.util.Properties argument can be used to pass arbitrary string tag/value pairs as
* connection arguments.</p>
*
* <ul>
* <li>user - (required) The user to connect as</li>
* <li>password - (optional) The password for the user</li>
* <li>ssl -(optional) Use SSL when connecting to the server</li>
* <li>readOnly - (optional) Set connection to read-only by default</li>
* <li>charSet - (optional) The character set to be used for converting to/from
* the database to unicode. If multibyte is enabled on the server then the character set of the
* database is used as the default, otherwise the jvm character encoding is used as the default.
* This value is only used when connecting to a 7.2 or older server.</li>
* <li>loglevel - (optional) Enable logging of messages from the driver. The value is an integer
* from 0 to 2 where: OFF = 0, INFO =1, DEBUG = 2 The output is sent to
* DriverManager.getPrintWriter() if set, otherwise it is sent to System.out.</li>
* <li>compatible - (optional) This is used to toggle between different functionality
* as it changes across different releases of the jdbc driver code. The values here are versions
* of the jdbc client and not server versions. For example in 7.1 get/setBytes worked on
* LargeObject values, in 7.2 these methods were changed to work on bytea values. This change in
* functionality could be disabled by setting the compatible level to be "7.1", in which case the
* driver will revert to the 7.1 functionality.</li>
* </ul>
*
* <p>Normally, at least "user" and "password" properties should be included in the properties. For a
* list of supported character encoding , see
* http://java.sun.com/products/jdk/1.2/docs/guide/internat/encoding.doc.html Note that you will
* probably want to have set up the Postgres database itself to use the same encoding, with the
* {@code -E <encoding>} argument to createdb.</p>
*
* <p>Our protocol takes the forms:</p>
*
* <pre>
* jdbc:postgresql://host:port/database?param1=val1&...
* </pre>
*
* @param url the URL of the database to connect to
* @param info a list of arbitrary tag/value pairs as connection arguments
* @return a connection to the URL or null if it isnt us
* @throws SQLException if a database access error occurs
* @see java.sql.Driver#connect
*/
@
Override
public
Connection connect(
String url,
Properties info) throws
SQLException {
// get defaults
Properties defaults;
if (!
url.
startsWith("jdbc:postgresql:")) {
return null;
}
try {
defaults =
getDefaultProperties();
} catch (
IOException ioe) {
throw new
PSQLException(
GT.
tr("Error loading default settings from driverconfig.properties"),
PSQLState.
UNEXPECTED_ERROR,
ioe);
}
// override defaults with provided properties
Properties props = new
Properties(
defaults);
if (
info != null) {
Set<
String>
e =
info.
stringPropertyNames();
for (
String propName :
e) {
String propValue =
info.
getProperty(
propName);
if (
propValue == null) {
throw new
PSQLException(
GT.
tr("Properties for the driver contains a non-string value for the key ")
+
propName,
PSQLState.
UNEXPECTED_ERROR);
}
props.
setProperty(
propName,
propValue);
}
}
// parse URL and add more properties
if ((
props =
parseURL(
url,
props)) == null) {
return null;
}
try {
// Setup java.util.logging.Logger using connection properties.
setupLoggerFromProperties(
props);
LOGGER.
log(
Level.
FINE, "Connecting with URL: {0}",
url);
// Enforce login timeout, if specified, by running the connection
// attempt in a separate thread. If we hit the timeout without the
// connection completing, we abandon the connection attempt in
// the calling thread, but the separate thread will keep trying.
// Eventually, the separate thread will either fail or complete
// the connection; at that point we clean up the connection if
// we managed to establish one after all. See ConnectThread for
// more details.
long
timeout =
timeout(
props);
if (
timeout <= 0) {
return
makeConnection(
url,
props);
}
ConnectThread ct = new
ConnectThread(
url,
props);
Thread thread = new
Thread(
ct, "PostgreSQL JDBC driver connection thread");
thread.
setDaemon(true); // Don't prevent the VM from shutting down
thread.
start();
return
ct.
getResult(
timeout);
} catch (
PSQLException ex1) {
LOGGER.
log(
Level.
FINE, "Connection error: ",
ex1);
// re-throw the exception, otherwise it will be caught next, and a
// org.postgresql.unusual error will be returned instead.
throw
ex1;
} catch (java.security.
AccessControlException ace) {
throw new
PSQLException(
GT.
tr(
"Your security policy has prevented the connection from being attempted. You probably need to grant the connect java.net.SocketPermission to the database server host and port that you wish to connect to."),
PSQLState.
UNEXPECTED_ERROR,
ace);
} catch (
Exception ex2) {
LOGGER.
log(
Level.
FINE, "Unexpected connection error: ",
ex2);
throw new
PSQLException(
GT.
tr(
"Something unusual has occurred to cause the driver to fail. Please report this exception."),
PSQLState.
UNEXPECTED_ERROR,
ex2);
}
}
// Used to check if the handler file is the same
private static
String loggerHandlerFile;
/**
* <p>Setup java.util.logging.Logger using connection properties.</p>
*
* <p>See {@link PGProperty#LOGGER_FILE} and {@link PGProperty#LOGGER_FILE}</p>
*
* @param props Connection Properties
*/
private void
setupLoggerFromProperties(final
Properties props) {
final
String driverLogLevel =
PGProperty.
LOGGER_LEVEL.
get(
props);
if (
driverLogLevel == null) {
return; // Don't mess with Logger if not set
}
if ("OFF".
equalsIgnoreCase(
driverLogLevel)) {
PARENT_LOGGER.
setLevel(
Level.
OFF);
return; // Don't mess with Logger if set to OFF
} else if ("DEBUG".
equalsIgnoreCase(
driverLogLevel)) {
PARENT_LOGGER.
setLevel(
Level.
FINE);
} else if ("TRACE".
equalsIgnoreCase(
driverLogLevel)) {
PARENT_LOGGER.
setLevel(
Level.
FINEST);
}
ExpressionProperties exprProps = new
ExpressionProperties(
props,
System.
getProperties());
final
String driverLogFile =
PGProperty.
LOGGER_FILE.
get(
exprProps);
if (
driverLogFile != null &&
driverLogFile.
equals(
loggerHandlerFile)) {
return; // Same file output, do nothing.
}
for (java.util.logging.
Handler handlers :
PARENT_LOGGER.
getHandlers()) {
// Remove previously set Handlers
handlers.
close();
PARENT_LOGGER.
removeHandler(
handlers);
loggerHandlerFile = null;
}
java.util.logging.
Handler handler = null;
if (
driverLogFile != null) {
try {
handler = new java.util.logging.
FileHandler(
driverLogFile);
loggerHandlerFile =
driverLogFile;
} catch (
Exception ex) {
System.
err.
println("Cannot enable FileHandler, fallback to ConsoleHandler.");
}
}
Formatter formatter = new
SimpleFormatter();
if (
handler == null ) {
if (
DriverManager.
getLogWriter() != null) {
handler = new
WriterHandler(
DriverManager.
getLogWriter());
} else if (
DriverManager.
getLogStream() != null) {
handler = new
StreamHandler(
DriverManager.
getLogStream(),
formatter);
} else {
handler = new
StreamHandler(
System.
err,
formatter);
}
} else {
handler.
setFormatter(
formatter);
}
handler.
setLevel(
PARENT_LOGGER.
getLevel());
PARENT_LOGGER.
setUseParentHandlers(false);
PARENT_LOGGER.
addHandler(
handler);
}
/**
* Perform a connect in a separate thread; supports getting the results from the original thread
* while enforcing a login timeout.
*/
private static class
ConnectThread implements
Runnable {
ConnectThread(
String url,
Properties props) {
this.
url =
url;
this.
props =
props;
}
public void
run() {
Connection conn;
Throwable error;
try {
conn =
makeConnection(
url,
props);
error = null;
} catch (
Throwable t) {
conn = null;
error =
t;
}
synchronized (this) {
if (
abandoned) {
if (
conn != null) {
try {
conn.
close();
} catch (
SQLException e) {
}
}
} else {
result =
conn;
resultException =
error;
notify();
}
}
}
/**
* Get the connection result from this (assumed running) thread. If the timeout is reached
* without a result being available, a SQLException is thrown.
*
* @param timeout timeout in milliseconds
* @return the new connection, if successful
* @throws SQLException if a connection error occurs or the timeout is reached
*/
public
Connection getResult(long
timeout) throws
SQLException {
long
expiry =
System.
currentTimeMillis() +
timeout;
synchronized (this) {
while (true) {
if (
result != null) {
return
result;
}
if (
resultException != null) {
if (
resultException instanceof
SQLException) {
resultException.
fillInStackTrace();
throw (
SQLException)
resultException;
} else {
throw new
PSQLException(
GT.
tr(
"Something unusual has occurred to cause the driver to fail. Please report this exception."),
PSQLState.
UNEXPECTED_ERROR,
resultException);
}
}
long
delay =
expiry -
System.
currentTimeMillis();
if (
delay <= 0) {
abandoned = true;
throw new
PSQLException(
GT.
tr("Connection attempt timed out."),
PSQLState.
CONNECTION_UNABLE_TO_CONNECT);
}
try {
wait(
delay);
} catch (
InterruptedException ie) {
// reset the interrupt flag
Thread.
currentThread().
interrupt();
abandoned = true;
// throw an unchecked exception which will hopefully not be ignored by the calling code
throw new
RuntimeException(
GT.
tr("Interrupted while attempting to connect."));
}
}
}
}
private final
String url;
private final
Properties props;
private
Connection result;
private
Throwable resultException;
private boolean
abandoned;
}
/**
* Create a connection from URL and properties. Always does the connection work in the current
* thread without enforcing a timeout, regardless of any timeout specified in the properties.
*
* @param url the original URL
* @param props the parsed/defaulted connection properties
* @return a new connection
* @throws SQLException if the connection could not be made
*/
private static
Connection makeConnection(
String url,
Properties props) throws
SQLException {
return new
PgConnection(
hostSpecs(
props),
user(
props),
database(
props),
props,
url);
}
/**
* Returns true if the driver thinks it can open a connection to the given URL. Typically, drivers
* will return true if they understand the subprotocol specified in the URL and false if they
* don't. Our protocols start with jdbc:postgresql:
*
* @param url the URL of the driver
* @return true if this driver accepts the given URL
* @see java.sql.Driver#acceptsURL
*/
@
Override
public boolean
acceptsURL(
String url) {
return
parseURL(
url, null) != null;
}
/**
* <p>The getPropertyInfo method is intended to allow a generic GUI tool to discover what properties
* it should prompt a human for in order to get enough information to connect to a database.</p>
*
* <p>Note that depending on the values the human has supplied so far, additional values may become
* necessary, so it may be necessary to iterate through several calls to getPropertyInfo</p>
*
* @param url the Url of the database to connect to
* @param info a proposed list of tag/value pairs that will be sent on connect open.
* @return An array of DriverPropertyInfo objects describing possible properties. This array may
* be an empty array if no properties are required
* @see java.sql.Driver#getPropertyInfo
*/
@
Override
public
DriverPropertyInfo[]
getPropertyInfo(
String url,
Properties info) {
Properties copy = new
Properties(
info);
Properties parse =
parseURL(
url,
copy);
if (
parse != null) {
copy =
parse;
}
PGProperty[]
knownProperties =
PGProperty.
values();
DriverPropertyInfo[]
props = new
DriverPropertyInfo[
knownProperties.length];
for (int
i = 0;
i <
props.length; ++
i) {
props[
i] =
knownProperties[
i].
toDriverPropertyInfo(
copy);
}
return
props;
}
@
Override
public int
getMajorVersion() {
return org.postgresql.util.
DriverInfo.
MAJOR_VERSION;
}
@
Override
public int
getMinorVersion() {
return org.postgresql.util.
DriverInfo.
MINOR_VERSION;
}
/**
* Returns the server version series of this driver and the specific build number.
*
* @return JDBC driver version
* @deprecated use {@link #getMajorVersion()} and {@link #getMinorVersion()} instead
*/
@
Deprecated
public static
String getVersion() {
return
DriverInfo.
DRIVER_FULL_NAME;
}
/**
* <p>Report whether the driver is a genuine JDBC compliant driver. A driver may only report "true"
* here if it passes the JDBC compliance tests, otherwise it is required to return false. JDBC
* compliance requires full support for the JDBC API and full support for SQL 92 Entry Level.</p>
*
* <p>For PostgreSQL, this is not yet possible, as we are not SQL92 compliant (yet).</p>
*/
@
Override
public boolean
jdbcCompliant() {
return false;
}
/**
* Constructs a new DriverURL, splitting the specified URL into its component parts.
*
* @param url JDBC URL to parse
* @param defaults Default properties
* @return Properties with elements added from the url
*/
public static
Properties parseURL(
String url,
Properties defaults) {
Properties urlProps = new
Properties(
defaults);
String l_urlServer =
url;
String l_urlArgs = "";
int
l_qPos =
url.
indexOf('?');
if (
l_qPos != -1) {
l_urlServer =
url.
substring(0,
l_qPos);
l_urlArgs =
url.
substring(
l_qPos + 1);
}
if (!
l_urlServer.
startsWith("jdbc:postgresql:")) {
LOGGER.
log(
Level.
FINE, "JDBC URL must start with \"jdbc:postgresql:\" but was: {0}",
url);
return null;
}
l_urlServer =
l_urlServer.
substring("jdbc:postgresql:".
length());
if (
l_urlServer.
startsWith("//")) {
l_urlServer =
l_urlServer.
substring(2);
int
slash =
l_urlServer.
indexOf('/');
if (
slash == -1) {
LOGGER.
log(
Level.
WARNING, "JDBC URL must contain a / at the end of the host or port: {0}",
url);
return null;
}
urlProps.
setProperty("PGDBNAME",
URLCoder.
decode(
l_urlServer.
substring(
slash + 1)));
String[]
addresses =
l_urlServer.
substring(0,
slash).
split(",");
StringBuilder hosts = new
StringBuilder();
StringBuilder ports = new
StringBuilder();
for (
String address :
addresses) {
int
portIdx =
address.
lastIndexOf(':');
if (
portIdx != -1 &&
address.
lastIndexOf(']') <
portIdx) {
String portStr =
address.
substring(
portIdx + 1);
try {
int
port =
Integer.
parseInt(
portStr);
if (
port < 1 ||
port > 65535) {
LOGGER.
log(
Level.
WARNING, "JDBC URL port: {0} not valid (1:65535) ",
portStr);
return null;
}
} catch (
NumberFormatException ignore) {
LOGGER.
log(
Level.
WARNING, "JDBC URL invalid port number: {0}",
portStr);
return null;
}
ports.
append(
portStr);
hosts.
append(
address.
subSequence(0,
portIdx));
} else {
ports.
append(
DEFAULT_PORT);
hosts.
append(
address);
}
ports.
append(',');
hosts.
append(',');
}
ports.
setLength(
ports.
length() - 1);
hosts.
setLength(
hosts.
length() - 1);
urlProps.
setProperty("PGPORT",
ports.
toString());
urlProps.
setProperty("PGHOST",
hosts.
toString());
} else {
/*
if there are no defaults set or any one of PORT, HOST, DBNAME not set
then set it to default
*/
if (
defaults == null || !
defaults.
containsKey("PGPORT")) {
urlProps.
setProperty("PGPORT",
DEFAULT_PORT);
}
if (
defaults == null || !
defaults.
containsKey("PGHOST")) {
urlProps.
setProperty("PGHOST", "localhost");
}
if (
defaults == null || !
defaults.
containsKey("PGDBNAME")) {
urlProps.
setProperty("PGDBNAME",
URLCoder.
decode(
l_urlServer));
}
}
// parse the args part of the url
String[]
args =
l_urlArgs.
split("&");
for (
String token :
args) {
if (
token.
isEmpty()) {
continue;
}
int
l_pos =
token.
indexOf('=');
if (
l_pos == -1) {
urlProps.
setProperty(
token, "");
} else {
urlProps.
setProperty(
token.
substring(0,
l_pos),
URLCoder.
decode(
token.
substring(
l_pos + 1)));
}
}
return
urlProps;
}
/**
* @return the address portion of the URL
*/
private static
HostSpec[]
hostSpecs(
Properties props) {
String[]
hosts =
props.
getProperty("PGHOST").
split(",");
String[]
ports =
props.
getProperty("PGPORT").
split(",");
HostSpec[]
hostSpecs = new
HostSpec[
hosts.length];
for (int
i = 0;
i <
hostSpecs.length; ++
i) {
hostSpecs[
i] = new
HostSpec(
hosts[
i],
Integer.
parseInt(
ports[
i]));
}
return
hostSpecs;
}
/**
* @return the username of the URL
*/
private static
String user(
Properties props) {
return
props.
getProperty("user", "");
}
/**
* @return the database name of the URL
*/
private static
String database(
Properties props) {
return
props.
getProperty("PGDBNAME", "");
}
/**
* @return the timeout from the URL, in milliseconds
*/
private static long
timeout(
Properties props) {
String timeout =
PGProperty.
LOGIN_TIMEOUT.
get(
props);
if (
timeout != null) {
try {
return (long) (
Float.
parseFloat(
timeout) * 1000);
} catch (
NumberFormatException e) {
LOGGER.
log(
Level.
WARNING, "Couldn't parse loginTimeout value: {0}",
timeout);
}
}
return (long)
DriverManager.
getLoginTimeout() * 1000;
}
/**
* This method was added in v6.5, and simply throws an SQLException for an unimplemented method. I
* decided to do it this way while implementing the JDBC2 extensions to JDBC, as it should help
* keep the overall driver size down. It now requires the call Class and the function name to help
* when the driver is used with closed software that don't report the stack strace
*
* @param callClass the call Class
* @param functionName the name of the unimplemented function with the type of its arguments
* @return PSQLException with a localized message giving the complete description of the
* unimplemeted function
*/
public static
SQLFeatureNotSupportedException notImplemented(
Class<?>
callClass,
String functionName) {
return new
SQLFeatureNotSupportedException(
GT.
tr("Method {0} is not yet implemented.",
callClass.
getName() + "." +
functionName),
PSQLState.
NOT_IMPLEMENTED.
getState());
}
//JCP! if mvn.project.property.postgresql.jdbc.spec >= "JDBC4.1"
@
Override
public java.util.logging.
Logger getParentLogger() {
return
PARENT_LOGGER;
}
//JCP! endif
public static
SharedTimer getSharedTimer() {
return
sharedTimer;
}
/**
* Register the driver against {@link DriverManager}. This is done automatically when the class is
* loaded. Dropping the driver from DriverManager's list is possible using {@link #deregister()}
* method.
*
* @throws IllegalStateException if the driver is already registered
* @throws SQLException if registering the driver fails
*/
public static void
register() throws
SQLException {
if (
isRegistered()) {
throw new
IllegalStateException(
"Driver is already registered. It can only be registered once.");
}
Driver registeredDriver = new
Driver();
DriverManager.
registerDriver(
registeredDriver);
Driver.
registeredDriver =
registeredDriver;
}
/**
* According to JDBC specification, this driver is registered against {@link DriverManager} when
* the class is loaded. To avoid leaks, this method allow unregistering the driver so that the
* class can be gc'ed if necessary.
*
* @throws IllegalStateException if the driver is not registered
* @throws SQLException if deregistering the driver fails
*/
public static void
deregister() throws
SQLException {
if (!
isRegistered()) {
throw new
IllegalStateException(
"Driver is not registered (or it has not been registered using Driver.register() method)");
}
DriverManager.
deregisterDriver(
registeredDriver);
registeredDriver = null;
}
/**
* @return {@code true} if the driver is registered against {@link DriverManager}
*/
public static boolean
isRegistered() {
return
registeredDriver != null;
}
}