com.jcorporate.expresso.core.db
Class SimpleDataSource

java.lang.Object
  com.jcorporate.expresso.core.db.SimpleDataSource

All Implemented Interfaces:

javax.sql.DataSource

public class SimpleDataSource

extends Object

implements javax.sql.DataSource

DataConnectionPool is an implementation of the javax.sql.DataSource. Normally you would get an instance of the DataConnectionPool using DBConnectionPool.getDataSource(String)

The reason for this class is that some libraries that can access a database often take a DataSource as their way of connecting to the database. Unfortunately, Expresso's DBConnectionPool's API is incompatible with the javax.sql.DataSource API. So this class wraps the DBConnectionPool with the DataSource interface so that libraries that require DataSource and Connection interfaces can operate within Expresso's database connection management capabilities.

Typical Usage:

javax.sql.DataSource dataSource = DBConnectionPool.getDataSource("default");
java.sql.Connection connection = dataSource.getConnection();
...
connection.close();


Author:

Michael Rimov

See Also:

DBConnectionPool, DBConnection

Constructor Summary

SimpleDataSource(DBConnectionPool newPoolInstance)
Wrapping constructor.

Method Summary

Connection	getConnection() Retreive a java.sql.Connection for this data source.
Connection	getConnection(String username, String password) [Unused] Normally would retrieve a connection with the given username and password.
protected DBConnectionPool	getConnectionPool() Helper method to retrieve the instance of the connectionPool we're attached to
int	getLoginTimeout() Retrieve the login timeout [unimplemented]
PrintWriter	getLogWriter() Retrieve the current logWriter.
void	setLoginTimeout(int seconds) Set the login timeout.
void	setLogWriter(PrintWriter out) Sets the log writer and thus turns on logging

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleDataSource

public SimpleDataSource(DBConnectionPool newPoolInstance)

Wrapping constructor. Takes a DBConnectionPool instance and wraps it for the DataSource implementation

Parameters:

newPoolInstance - the instance of the DBConnectionPool

Method Detail

getConnectionPool

protected DBConnectionPool getConnectionPool()

Helper method to retrieve the instance of the connectionPool we're attached to

Returns:

DBConnectionPool instance

getConnection

public Connection getConnection()
                         throws SQLException

Retreive a java.sql.Connection for this data source. It does not attempt to retrieve pooled connections.

Specified by:

getConnection in interface javax.sql.DataSource

Returns:

java.sql.Connection

Throws:

SQLException - upon error getting the connection

getConnection

public Connection getConnection(String username,
                                String password)
                         throws SQLException

[Unused]

Normally would retrieve a connection with the given username and password. However, that is not possible with the Expresso's DBConnectionPool which manages the default username and password as given in the configuration file. So this implementation logs a warning about this method and falls back to getConnection()

Specified by:

getConnection in interface javax.sql.DataSource

Parameters:

username - the user name for the connection

password - the password for the connection

Returns:

java.sql.Connection implementation

Throws:

SQLException - upon connection error

See Also:

getConnection()

getLogWriter

public PrintWriter getLogWriter()
                         throws SQLException

Retrieve the current logWriter. Default is null

Specified by:

getLogWriter in interface javax.sql.DataSource

Returns:

java.io.PrintWriter for the current log writer

Throws:

SQLException - upon error

setLogWriter

public void setLogWriter(PrintWriter out)
                  throws SQLException

Sets the log writer and thus turns on logging

Specified by:

setLogWriter in interface javax.sql.DataSource

Parameters:

out - the new print writer to log getConnection() calls to.

Throws:

SQLException - upon error

setLoginTimeout

public void setLoginTimeout(int seconds)
                     throws SQLException

Set the login timeout. [unimplemented]

Specified by:

setLoginTimeout in interface javax.sql.DataSource

Parameters:

seconds - the number of seconds to wait before logins timeout

Throws:

SQLException - upon error

getLoginTimeout

public int getLoginTimeout()
                    throws SQLException

Retrieve the login timeout [unimplemented]

Specified by:

getLoginTimeout in interface javax.sql.DataSource

Returns:

number of seconds before login timeout occurs (zero)

Throws:

SQLException - upon error