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 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 Also
Public Method Summary
synchronized static void | |
static Connection | |
static Connection |
getConnection(String url, String user, String password)
Attempts to establish a connection to the given database URL.
|
static Connection |
getConnection(String url, Properties info)
Attempts to establish a connection to the given database URL.
|
static Driver | |
static Enumeration<Driver> |
getDrivers()
Retrieves an Enumeration with all of the currently loaded JDBC drivers
to which the current caller has access.
|
static PrintStream |
getLogStream()
This method is deprecated.
Use
getLogWriter instead. |
static PrintWriter |
getLogWriter()
Retrieves the log writer.
|
static int |
getLoginTimeout()
Gets the maximum time in seconds that a driver can wait
when attempting to log in to a database.
|
static void | |
synchronized static void | |
static void | |
static void |
setLogWriter(PrintWriter out)
Sets the logging/tracing
PrintWriter object
that is used by the DriverManager and all drivers. |
static void |
setLoginTimeout(int seconds)
Sets the maximum time in seconds that a driver will wait
while attempting to connect to a database.
|
Inherited Method Summary
Public Methods
public static synchronized void deregisterDriver (Driver driver)
Drops a driver from the DriverManager
's list.
Applets can only deregister drivers from their own classloaders.
Parameters
driver | the JDBC Driver to drop |
---|
Throws
SQLException | if a database access error occurs |
---|
public static Connection getConnection (String url)
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.
Parameters
url | a database url of the form
jdbc:subprotocol:subname |
---|
Returns
- a connection to the URL
Throws
SQLException | if a database access error occurs |
---|
public static Connection getConnection (String url, String user, String password)
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.
Parameters
url | a database url of the form
jdbc:subprotocol:subname |
---|---|
user | the database user on whose behalf the connection is being made |
password | the user's password |
Returns
- a connection to the URL
Throws
SQLException | if a database access error occurs |
---|
public static Connection getConnection (String url, Properties info)
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.
Parameters
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 included |
Returns
- a Connection to the URL
Throws
SQLException | if a database access error occurs |
---|
public static Driver getDriver (String url)
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.
Parameters
url | a database URL of the form
jdbc:subprotocol:subname |
---|
Returns
- a
Driver
object representing a driver that can connect to the given URL
Throws
SQLException | if a database access error occurs |
---|
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()
Returns
- the list of JDBC Drivers loaded by the caller's class loader
public static PrintStream getLogStream ()
This method is deprecated.
Use getLogWriter
instead.
Retrieves the logging/tracing PrintStream that is used by the DriverManager
and all drivers.
Returns
- the logging/tracing PrintStream; if disabled, is
null
See Also
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.
Returns
- a
java.io.PrintWriter
object
See Also
public static int getLoginTimeout ()
Gets the maximum time in seconds that a driver can wait when attempting to log in to a database.
Returns
- the driver login time limit in seconds
See Also
public static void println (String message)
Prints a message to the current JDBC log stream.
Parameters
message | a log or tracing message |
---|
public static synchronized void registerDriver (Driver driver)
Registers the given driver with the DriverManager
.
A newly-loaded driver class should call
the method registerDriver
to make itself
known to the DriverManager
.
Parameters
driver | the new JDBC Driver that is to be registered with the
DriverManager |
---|
Throws
SQLException | if a database access error occurs |
---|
public static void setLogStream (PrintStream out)
This method is deprecated.
Use setLogWriter
instead.
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
.
Parameters
out | the new logging/tracing PrintStream; to disable, set to null |
---|
Throws
SecurityException | if a security manager exists and its
checkPermission method denies setting the log stream |
---|
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
.
Parameters
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 |
---|
public static void setLoginTimeout (int seconds)
Sets the maximum time in seconds that a driver will wait while attempting to connect to a database.
Parameters
seconds | the login time limit in seconds; zero means there is no limit |
---|