java.sql

Class DriverManager


  • 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".

    See Also:
    Driver, Connection

    • Method Detail

      • 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:
        a java.io.PrintWriter object
        Since:
        1.2
        See Also:
        setLogWriter(java.io.PrintWriter)

      • 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 - 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
        Since:
        1.2
        See Also:
        SecurityManager.checkPermission(java.security.Permission), getLogWriter()

      • getConnection

        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.

        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 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 attempt

      • getConnection

        public 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.

        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 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 attempt

      • getConnection

        public 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.
        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 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 attempt

      • getDriver

        public 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.
        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

      • registerDriver

        public 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.
        Parameters:
        driver - the new JDBC Driver that is to be registered with the DriverManager
        Throws:
        SQLException - if a database access error occurs
        NullPointerException - if driver is null

      • registerDriver

        public 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.
        Parameters:
        driver - the new JDBC Driver that is to be registered with the DriverManager
        da - the DriverAction implementation to be used when DriverManager#deregisterDriver is called
        Throws:
        SQLException - if a database access error occurs
        NullPointerException - if driver is null
        Since:
        1.8

      • deregisterDriver

        public 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.

        Parameters:
        driver - the JDBC Driver to remove
        Throws:
        SQLException - if a database access error occurs
        SecurityException - if a security manager exists and its checkPermission method denies permission to deregister a driver.
        See Also:
        SecurityManager.checkPermission(java.security.Permission)

      • 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:
        the list of JDBC Drivers loaded by the caller's class loader

      • 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 once the driver has been identified.
        Parameters:
        seconds - the login time limit in seconds; zero means there is no limit
        See Also:
        getLoginTimeout()

      • 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:
        the driver login time limit in seconds
        See Also:
        setLoginTimeout(int)

      • setLogStream

        @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.

        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
        See Also:
        SecurityManager.checkPermission(java.security.Permission), getLogStream()

      • getLogStream

        @Deprecated
public static PrintStream getLogStream()
        Deprecated.  Use getLogWriter
        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:
        setLogStream(java.io.PrintStream)

      • println

        public static void println(String message)
        Prints a message to the current JDBC log stream.
        Parameters:
        message - a log or tracing message