public class DriverManager extends Object
The basic service for managing a set of JDBC drivers.
NOTE: The 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 explicitly 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"
.
Driver
, Connection
public static PrintWriter getLogWriter()
Retrieves the log writer. The getLogWriter
and setLogWriter
methods should be used instead of the get/setlogStream
methods, which are deprecated.
java.io.PrintWriter
objectsetLogWriter(java.io.PrintWriter)
public static void setLogWriter(PrintWriter out)
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
.
out
- the new logging/tracing PrintStream
object; null
to disable logging and tracingSecurityException
- if a security manager exists and its checkPermission
method denies setting the log writerSecurityManager.checkPermission(java.security.Permission)
, getLogWriter()
public static Connection getConnection(String url, Properties info) throws SQLException
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.
Note: If a property is specified as part of the url
and is also specified in the Properties
object, it is implementation-defined as to which value will take precedence. For maximum portability, an application should only specify a property once.
url
- a database url of the form jdbc:subprotocol:subname
info
- a list of arbitrary string tag/value pairs as connection arguments; normally at least a "user" and "password" property should be includedSQLException
- if a database access error occurs or the url is null
SQLTimeoutException
- when the driver has determined that the timeout value specified by the setLoginTimeout
method has been exceeded and has at least tried to cancel the current database connection attemptpublic static Connection getConnection(String url, String user, String password) throws SQLException
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.
Note: If the user
or password
property are also specified as part of the url
, it is implementation-defined as to which value will take precedence. For maximum portability, an application should only specify a property once.
url
- a database url of the form jdbc:subprotocol:subname
user
- the database user on whose behalf the connection is being madepassword
- the user's passwordSQLException
- if a database access error occurs or the url is null
SQLTimeoutException
- when the driver has determined that the timeout value specified by the setLoginTimeout
method has been exceeded and has at least tried to cancel the current database connection attemptpublic static Connection getConnection(String url) throws SQLException
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.
url
- a database url of the form jdbc:subprotocol:subname
SQLException
- if a database access error occurs or the url is null
SQLTimeoutException
- when the driver has determined that the timeout value specified by the setLoginTimeout
method has been exceeded and has at least tried to cancel the current database connection attemptpublic static Driver getDriver(String url) throws SQLException
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.
url
- a database URL of the form jdbc:subprotocol:subname
Driver
object representing a driver that can connect to the given URLSQLException
- if a database access error occurspublic static void registerDriver(Driver driver) throws SQLException
Registers the given driver with the DriverManager
. A newly-loaded driver class should call the method registerDriver
to make itself known to the DriverManager
. If the driver is currently registered, no action is taken.
driver
- the new JDBC Driver that is to be registered with the DriverManager
SQLException
- if a database access error occursNullPointerException
- if driver
is nullpublic static void registerDriver(Driver driver, DriverAction da) throws SQLException
Registers the given driver with the DriverManager
. A newly-loaded driver class should call the method registerDriver
to make itself known to the DriverManager
. If the driver is currently registered, no action is taken.
driver
- the new JDBC Driver that is to be registered with the DriverManager
da
- the DriverAction
implementation to be used when DriverManager#deregisterDriver
is calledSQLException
- if a database access error occursNullPointerException
- if driver
is nullpublic static void deregisterDriver(Driver driver) throws SQLException
Removes the specified driver from the DriverManager
's list of registered drivers.
If a null
value is specified for the driver to be removed, then no action is taken.
If a security manager exists and its checkPermission
denies permission, then a SecurityException
will be thrown.
If the specified driver is not found in the list of registered drivers, then no action is taken. If the driver was found, it will be removed from the list of registered drivers.
If a DriverAction
instance was specified when the JDBC driver was registered, its deregister method will be called prior to the driver being removed from the list of registered drivers.
driver
- the JDBC Driver to removeSQLException
- if a database access error occursSecurityException
- if a security manager exists and its checkPermission
method denies permission to deregister a driver.SecurityManager.checkPermission(java.security.Permission)
public static Enumeration<Driver> getDrivers()
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()
public static void setLoginTimeout(int seconds)
Sets the maximum time in seconds that a driver will wait while attempting to connect to a database once the driver has been identified.
seconds
- the login time limit in seconds; zero means there is no limitgetLoginTimeout()
public static int getLoginTimeout()
Gets the maximum time in seconds that a driver can wait when attempting to log in to a database.
setLoginTimeout(int)
@Deprecated public static void setLogStream(PrintStream out)
Deprecated. Use setLogWriter
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
.
out
- the new logging/tracing PrintStream; to disable, set to null
SecurityException
- if a security manager exists and its checkPermission
method denies setting the log streamSecurityManager.checkPermission(java.security.Permission)
, getLogStream()
@Deprecated public static PrintStream getLogStream()
Deprecated. Use getLogWriter
Retrieves the logging/tracing PrintStream that is used by the DriverManager
and all drivers.
null
setLogStream(java.io.PrintStream)
public static void println(String message)
Prints a message to the current JDBC log stream.
message
- a log or tracing message
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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