Class Driver

  • All Implemented Interfaces:
    java.sql.Driver

    public class Driver
    extends java.lang.Object
    implements java.sql.Driver

    The Java SQL framework allows for multiple database drivers. Each driver should supply a class that implements the Driver interface

    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.

    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.

    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")

    See Also:
    PGConnection, Driver
    • Constructor Summary

      Constructors 
      Constructor Description
      Driver()  
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      boolean acceptsURL​(java.lang.String url)
      Returns true if the driver thinks it can open a connection to the given URL.
      java.sql.Connection connect​(java.lang.String url, java.util.Properties info)
      Try to make a database connection to the given URL.
      static void deregister()
      According to JDBC specification, this driver is registered against DriverManager when the class is loaded.
      int getMajorVersion()  
      int getMinorVersion()  
      java.util.logging.Logger getParentLogger()  
      java.sql.DriverPropertyInfo[] getPropertyInfo​(java.lang.String url, java.util.Properties info)
      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.
      static SharedTimer getSharedTimer()  
      static java.lang.String getVersion()
      Deprecated.
      static boolean isRegistered()  
      boolean jdbcCompliant()
      Report whether the driver is a genuine JDBC compliant driver.
      static java.sql.SQLFeatureNotSupportedException notImplemented​(java.lang.Class<?> callClass, java.lang.String functionName)
      This method was added in v6.5, and simply throws an SQLException for an unimplemented method.
      static java.util.Properties parseURL​(java.lang.String url, java.util.Properties defaults)
      Constructs a new DriverURL, splitting the specified URL into its component parts.
      static void register()
      Register the driver against DriverManager.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • Driver

        public Driver()
    • Method Detail

      • connect

        public java.sql.Connection connect​(java.lang.String url,
                                           java.util.Properties info)
                                    throws java.sql.SQLException

        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.

        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.

        The java.util.Properties argument can be used to pass arbitrary string tag/value pairs as connection arguments.

        • user - (required) The user to connect as
        • password - (optional) The password for the user
        • ssl -(optional) Use SSL when connecting to the server
        • readOnly - (optional) Set connection to read-only by default
        • 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.
        • 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.
        • 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.

        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 -E <encoding> argument to createdb.

        Our protocol takes the forms:

          jdbc:postgresql://host:port/database?param1=val1&...
         
        Specified by:
        connect in interface java.sql.Driver
        Parameters:
        url - the URL of the database to connect to
        info - a list of arbitrary tag/value pairs as connection arguments
        Returns:
        a connection to the URL or null if it isnt us
        Throws:
        java.sql.SQLException - if a database access error occurs or the url is null
        See Also:
        Driver.connect(java.lang.String, java.util.Properties)
      • acceptsURL

        public boolean acceptsURL​(java.lang.String 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:
        Specified by:
        acceptsURL in interface java.sql.Driver
        Parameters:
        url - the URL of the driver
        Returns:
        true if this driver accepts the given URL
        See Also:
        Driver.acceptsURL(java.lang.String)
      • getPropertyInfo

        public java.sql.DriverPropertyInfo[] getPropertyInfo​(java.lang.String url,
                                                             java.util.Properties info)

        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.

        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

        Specified by:
        getPropertyInfo in interface java.sql.Driver
        Parameters:
        url - the Url of the database to connect to
        info - a proposed list of tag/value pairs that will be sent on connect open.
        Returns:
        An array of DriverPropertyInfo objects describing possible properties. This array may be an empty array if no properties are required
        See Also:
        Driver.getPropertyInfo(java.lang.String, java.util.Properties)
      • getMajorVersion

        public int getMajorVersion()
        Specified by:
        getMajorVersion in interface java.sql.Driver
      • getMinorVersion

        public int getMinorVersion()
        Specified by:
        getMinorVersion in interface java.sql.Driver
      • getVersion

        @Deprecated
        public static java.lang.String getVersion()
        Deprecated.
        Returns the server version series of this driver and the specific build number.
        Returns:
        JDBC driver version
      • jdbcCompliant

        public boolean jdbcCompliant()

        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.

        For PostgreSQL, this is not yet possible, as we are not SQL92 compliant (yet).

        Specified by:
        jdbcCompliant in interface java.sql.Driver
      • parseURL

        public static java.util.Properties parseURL​(java.lang.String url,
                                                    java.util.Properties defaults)
        Constructs a new DriverURL, splitting the specified URL into its component parts.
        Parameters:
        url - JDBC URL to parse
        defaults - Default properties
        Returns:
        Properties with elements added from the url
      • notImplemented

        public static java.sql.SQLFeatureNotSupportedException notImplemented​(java.lang.Class<?> callClass,
                                                                              java.lang.String functionName)
        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
        Parameters:
        callClass - the call Class
        functionName - the name of the unimplemented function with the type of its arguments
        Returns:
        PSQLException with a localized message giving the complete description of the unimplemeted function
      • getParentLogger

        public java.util.logging.Logger getParentLogger()
        Specified by:
        getParentLogger in interface java.sql.Driver
      • getSharedTimer

        public static SharedTimer getSharedTimer()
      • register

        public static void register()
                             throws java.sql.SQLException
        Register the driver against DriverManager. This is done automatically when the class is loaded. Dropping the driver from DriverManager's list is possible using deregister() method.
        Throws:
        java.lang.IllegalStateException - if the driver is already registered
        java.sql.SQLException - if registering the driver fails
      • deregister

        public static void deregister()
                               throws java.sql.SQLException
        According to JDBC specification, this driver is registered against 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:
        java.lang.IllegalStateException - if the driver is not registered
        java.sql.SQLException - if deregistering the driver fails
      • isRegistered

        public static boolean isRegistered()
        Returns:
        true if the driver is registered against DriverManager