DriverManager
public
class
DriverManager
extends Object
java.lang.Object | |
↳ | java.sql.DriverManager |
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:
Summary
Public methods | |
---|---|
static
void
|
deregisterDriver(Driver driver)
Drops a driver from the |
static
Connection
|
getConnection(String url)
Attempts to establish a connection to the given database URL. |
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
|
getDriver(String url)
Attempts to locate a driver that understands the given URL. |
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 was deprecated
in API level 15.
Use |
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
|
println(String message)
Prints a message to the current JDBC log stream. |
static
void
|
registerDriver(Driver driver)
Registers the given driver with the |
static
void
|
setLogStream(PrintStream out)
This method was deprecated
in API level 15.
Use |
static
void
|
setLogWriter(PrintWriter out)
Sets the logging/tracing |
static
void
|
setLoginTimeout(int seconds)
Sets the maximum time in seconds that a driver will wait while attempting to connect to a database. |
Inherited methods | |
---|---|
Public methods
deregisterDriver
public static void deregisterDriver (Driver driver)
Drops a driver from the DriverManager
's list.
Applets can only deregister drivers from their own classloaders.
Parameters | |
---|---|
driver |
Driver : the JDBC Driver to drop |
Throws | |
---|---|
SQLException |
if a database access error occurs |
getConnection
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 |
String : a database url of the form
jdbc:subprotocol:subname |
Returns | |
---|---|
Connection |
a connection to the URL |
Throws | |
---|---|
SQLException |
if a database access error occurs |
getConnection
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 |
String : a database url of the form
jdbc:subprotocol:subname |
user |
String : the database user on whose behalf the connection is being
made |
password |
String : the user's password |
Returns | |
---|---|
Connection |
a connection to the URL |
Throws | |
---|---|
SQLException |
if a database access error occurs |
getConnection
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 |
String : a database url of the form
jdbc:subprotocol:subname |
info |
Properties : a list of arbitrary string tag/value pairs as
connection arguments; normally at least a "user" and
"password" property should be included |
Returns | |
---|---|
Connection |
a Connection to the URL |
Throws | |
---|---|
SQLException |
if a database access error occurs |
getDriver
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 |
String : a database URL of the form
jdbc:subprotocol:subname |
Returns | |
---|---|
Driver |
a Driver object representing a driver
that can connect to the given URL |
Throws | |
---|---|
SQLException |
if a database access error occurs |
getDrivers
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 | |
---|---|
Enumeration<Driver> |
the list of JDBC Drivers loaded by the caller's class loader |
getLogStream
public static PrintStream getLogStream ()
This method was deprecated
in API level 15.
Use getLogWriter
instead.
Retrieves the logging/tracing PrintStream that is used by the DriverManager
and all drivers.
Returns | |
---|---|
PrintStream |
the logging/tracing PrintStream; if disabled, is null |
See also:
getLogWriter
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 | |
---|---|
PrintWriter |
a java.io.PrintWriter object |
See also:
getLoginTimeout
public static int getLoginTimeout ()
Gets the maximum time in seconds that a driver can wait when attempting to log in to a database.
Returns | |
---|---|
int |
the driver login time limit in seconds |
See also:
println
public static void println (String message)
Prints a message to the current JDBC log stream.
Parameters | |
---|---|
message |
String : a log or tracing message |
registerDriver
public static 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 |
Driver : the new JDBC Driver that is to be registered with the
DriverManager |
Throws | |
---|---|
SQLException |
if a database access error occurs |
setLogStream
public static void setLogStream (PrintStream out)
This method was deprecated
in API level 15.
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 |
PrintStream : 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 |
setLogWriter
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 |
PrintWriter : 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 |
setLoginTimeout
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 |
int : the login time limit in seconds; zero means there is no limit |
See also: