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package postgresql;
import java.sql.*;
import java.util.*;
import postgresql.*;
/**
* @version 1.0 15-APR-1997
* @author <A HREF="mailto:[email protected]">Adrian Hall</A>
*
* 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 postgresql.Connection
* @see java.sql.Driver
*/
public class Driver implements java.sql.Driver
{
static
{
try
{
new Driver();
} catch (SQLException e) {
e.printStackTrace();
}
}
/**
* Construct a new driver and register it with DriverManager
*
* @exception SQLException for who knows what!
*/
public Driver() throws SQLException
{
java.sql.DriverManager.registerDriver(this);
}
/**
* 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. Normally, at least
* "user" and "password" properties should be included in the
* properties.
*
* Our protocol takes the form:
* <PRE>
* jdbc:postgresql://host:port/database
* </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
{
DriverURL dr = new DriverURL(url);
int port;
if (!(dr.protocol().equals("jdbc")))
return null;
if (!(dr.subprotocol().equals("postgresql")))
return null;
if (dr.host().equals("unknown"))
return null;
port = dr.port();
if (port == -1)
port = 5432; // Default PostgreSQL port
return new Connection (dr.host(), port, info, dr.database(), url, this);
}
/**
* 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:
*
* @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
{
DriverURL dr = new DriverURL(url);
if (dr.protocol().equals("jdbc"))
if (dr.subprotocol().equals("postgresql"))
return true;
return false;
}
/**
* 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
*
* @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 null; // We don't need anything except
// the username, which is a default
}
/**
* Gets the drivers major version number
*
* @return the drivers major version number
*/
public int getMajorVersion()
{
return 1;
}
/**
* Get the drivers minor version number
*
* @return the drivers minor version number
*/
public int getMinorVersion()
{
return 0;
}
/**
* 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.
*/
public boolean jdbcCompliant()
{
return false;
}
}
/**
* The DriverURL class splits a JDBC URL into its subcomponents
*
* protocol:subprotocol:/[/host[:port]/][database]
*/
class DriverURL
{
private String protocol, subprotocol, host, database;
private int port = -1;
/**
* Constructs a new DriverURL, splitting the specified URL into its
* component parts
*/
public DriverURL(String url) throws SQLException
{
int a, b, c;
String tmp, hostport, dbportion;
a = url.indexOf(':');
if (a == -1)
throw new SQLException("Bad URL Protocol specifier");
b = url.indexOf(':', a+1);
if (b == -1)
throw new SQLException("Bad URL Subprotocol specifier");
protocol = new String(url.substring(0, a));
subprotocol = new String(url.substring(a+1, b));
tmp = new String(url.substring(b+1, url.length()));
if (tmp.length() < 2)
throw new SQLException("Bad URL Database specifier");
if (!tmp.substring(0, 2).equals("//"))
{
host = new String("unknown");
port = -1;
database = new String(tmp.substring(1, tmp.length()));
return;
}
dbportion = new String(tmp.substring(2, tmp.length()));
c = dbportion.indexOf('/');
if (c == -1)
throw new SQLException("Bad URL Database specifier");
a = dbportion.indexOf(':');
if (a == -1)
{
host = new String(dbportion.substring(0, c));
port = -1;
database = new String(dbportion.substring(c+1, dbportion.length()));
} else {
host = new String(dbportion.substring(0, a));
port = Integer.valueOf(dbportion.substring(a+1, c)).intValue();
database = new String(dbportion.substring(c+1, dbportion.length()));
}
}
/**
* Returns the protocol name of the DriverURL
*/
public String protocol()
{
return protocol;
}
/**
* Returns the subprotocol name of the DriverURL
*/
public String subprotocol()
{
return subprotocol;
}
/**
* Returns the hostname portion of the URL
*/
public String host()
{
return host;
}
/**
* Returns the port number portion of the URL
* or -1 if no port was specified
*/
public int port()
{
return port;
}
/**
* Returns the database name of the URL
*/
public String database()
{
return database;
}
}
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