postgresjdbcdriver.java

基于JAVA的一个注册系统 最初只是为了公司做演示使用

package net.yefei.cmn.db;

import java.sql.*;
import java.util.*;

import org.postgresql.*;

/*
 * The Java SQL framework allows for multiple database drivers.  Each
 * driver should supply a class that implements the Driver interface
 *
 * <p>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.
 *
 * <p>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.
 *
 * <p>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 org.postgresql.Connection
 * @see java.sql.Driver
 */
public class PostgresJDBCDriver implements java.sql.Driver
{
	
	static
	{
		try
		{
			// moved the registerDriver from the constructor to here
			// because some clients call the driver themselves (I know, as
			// my early jdbc work did - and that was based on other examples).
			// Placing it here, means that the driver is registered once only.
			java.sql.DriverManager.registerDriver(new PostgresJDBCDriver());

		}
		catch (SQLException e)
		{
			e.printStackTrace();
		}
	}
	private java.sql.Driver psqlDriver ; 

	/*
	 * Construct a new driver and register it with DriverManager
	 *
	 * @exception SQLException for who knows what!
	 */
	public PostgresJDBCDriver() throws SQLException
	{
		psqlDriver = new org.postgresql.Driver();
	}
	private void addDataTypes(org.postgresql.Connection c){
		c.addDataType("inet", "org.postgresql.util.PGobject");
		c.addDataType("_inet", "org.postgresql.util.PGobject");
		c.addDataType("cidr", "org.postgresql.util.PGobject");
		c.addDataType("_cidr", "org.postgresql.util.PGobject");
		c.addDataType("macaddr", "org.postgresql.util.PGobject");
		c.addDataType("_macaddr", "org.postgresql.util.PGobject");
	}

	/*
	 * 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.
	 *
	 * <p>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.
	 *
	 * <p>The java.util.Properties argument can be used to pass arbitrary
	 * string tag/value pairs as connection arguments.
	 *
	 * user - (optional) The user to connect as
	 * password - (optional) The password for the user
	 * 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.
	 * compatible - 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.
	 *
	 * <p>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:
	 * <PRE>
	 *	jdbc:org.postgresql://host:port/database?param1=val1&...
	 * </PRE>
	 *
	 * @param url the URL of the database to connect to
	 * @param info a list of arbitrary tag/value pairs as connection
	 *	arguments
	 * @return a connection to the URL or null if it isnt us
	 * @exception SQLException if a database access error occurs
	 * @see java.sql.Driver#connect
	 */
	public java.sql.Connection connect(String url, Properties info) throws SQLException
	{
		org.postgresql.Connection c = (org.postgresql.Connection)psqlDriver.connect(url, info);
		addDataTypes(c);
		return (java.sql.Connection)c;
	}

	/*
	 * 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:org.postgresql:
	 *
	 * @see java.sql.Driver#acceptsURL
	 * @param url the URL of the driver
	 * @return true if this driver accepts the given URL
	 * @exception SQLException if a database-access error occurs
	 *	(Dont know why it would *shrug*)
	 */
	public boolean acceptsURL(String url) throws SQLException
	{
		return psqlDriver.acceptsURL(url);
	}

	/*
	 * 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.
	 *
	 * <p>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
	 *
	 * @param url the Url of the database to connect to
	 * @param info a proposed list of tag/value pairs that will be sent on
	 *	connect open.
	 * @return An array of DriverPropertyInfo objects describing
	 *	possible properties.  This array may be an empty array if
	 *	no properties are required
	 * @exception SQLException if a database-access error occurs
	 * @see java.sql.Driver#getPropertyInfo
	 */
	public DriverPropertyInfo[] getPropertyInfo(String url, Properties info) throws SQLException
	{
		return psqlDriver.getPropertyInfo(url, info);
	}

	/*
	 * Gets the drivers major version number
	 *
	 * @return the drivers major version number
	 */
	public int getMajorVersion()
	{
		return psqlDriver.getMajorVersion();
	}

	/*
	 * Get the drivers minor version number
	 *
	 * @return the drivers minor version number
	 */
	public int getMinorVersion()
	{
		return psqlDriver.getMinorVersion();
	}

	/*
	 * 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.
	 *
	 * <p>For PostgreSQL, this is not yet possible, as we are not SQL92
	 * compliant (yet).
	 */
	public boolean jdbcCompliant()
	{
		return psqlDriver.jdbcCompliant();
	}

}