org.postgresql
Class Driver

java.lang.Object
  org.postgresql.Driver

All Implemented Interfaces:

Driver

public class Driver
extends Object
implements 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

Field Summary

static int	DEBUG
static int	INFO
static int	MAJORVERSION
static int	MINORVERSION

Constructor Summary

Driver()

Method Summary

boolean	acceptsURL(String url) Returns true if the driver thinks it can open a connection to the given URL.
Connection	connect(String url, Properties info) Try to make a database connection to the given URL.
static int	getLogLevel()
int	getMajorVersion() Gets the drivers major version number
int	getMinorVersion() Get the drivers minor version number
Logger	getParentLogger()
DriverPropertyInfo[]	getPropertyInfo(String url, 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 String	getVersion() Returns the server version series of this driver and the specific build number.
boolean	jdbcCompliant() Report whether the driver is a genuine JDBC compliant driver.
static SQLFeatureNotSupportedException	notImplemented(Class callClass, String functionName)
static void	setLogLevel(int logLevel) used to turn logging on to a certain level, can be called by specifying fully qualified class ie org.postgresql.Driver.setLogLevel()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEBUG

public static final int DEBUG

See Also:

Constant Field Values

INFO

public static final int INFO

See Also:

Constant Field Values

MAJORVERSION

public static final int MAJORVERSION

See Also:

Constant Field Values

MINORVERSION

public static final int MINORVERSION

See Also:

Constant Field Values

Constructor Detail

Driver

public Driver()

Method Detail

connect

public Connection connect(String url,
                          Properties info)
                   throws 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 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 1 to 2 where: 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 " argument to createdb. Our protocol takes the forms:

 jdbc:postgresql://host:port/database?param1=val1&...
 

Specified by:

connect in interface 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:

SQLException - if a database access error occurs

See Also:

Driver.connect(java.lang.String, java.util.Properties)

acceptsURL

public boolean acceptsURL(String url)
                   throws SQLException

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 Driver

Parameters:

url - the URL of the driver

Returns:

true if this driver accepts the given URL

Throws:

SQLException - if a database-access error occurs (Dont know why it would *shrug*)

See Also:

Driver.acceptsURL(java.lang.String)

getPropertyInfo

public DriverPropertyInfo[] getPropertyInfo(String url,
                                            Properties info)
                                     throws SQLException

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 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

Throws:

SQLException - if a database-access error occurs

See Also:

Driver.getPropertyInfo(java.lang.String, java.util.Properties)

getMajorVersion

public int getMajorVersion()

Gets the drivers major version number

Specified by:

getMajorVersion in interface Driver

Returns:

the drivers major version number

getMinorVersion

public int getMinorVersion()

Get the drivers minor version number

Specified by:

getMinorVersion in interface Driver

Returns:

the drivers minor version number

getVersion

public static String getVersion()

Returns the server version series of this driver and the specific build number.

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 Driver

notImplemented

public static SQLFeatureNotSupportedException notImplemented(Class callClass,
                                                             String functionName)

setLogLevel

public static void setLogLevel(int logLevel)

used to turn logging on to a certain level, can be called by specifying fully qualified class ie org.postgresql.Driver.setLogLevel()

Parameters:

logLevel - sets the level which logging will respond to INFO being almost no messages DEBUG most verbose

getLogLevel

public static int getLogLevel()

getParentLogger

public Logger getParentLogger()
                       throws SQLFeatureNotSupportedException

Throws:

SQLFeatureNotSupportedException