org.paneris.jal.model
Class DBConnectionManager

java.lang.Object
  org.paneris.jal.model.DBConnectionManager

public class DBConnectionManager
extends java.lang.Object

This class is a Singleton that provides access to one or many connection pools for databases defined in a Property file. A client gets access to the single instance through the static getInstance() method and can then check-out and check-in connections from a pool. When the client shuts down it should call the release() method to close all open connections and do other clean up.

Field Summary

static int	ACCESS
static int	MYSQL
static int	POSTGRES
static int	UNKNOWN Constants representing different RDBMSs

Method Summary

void	freeConnection(java.lang.String name, java.sql.Connection con) Returns a connection to the named pool.
java.sql.Connection	getConnection(java.lang.String callingClass, java.lang.String name) Returns an open connection.
java.sql.Connection	getConnection(java.lang.String callingClass, java.lang.String name, long time) Returns an open connection.
int	getDatabaseEngineType(java.lang.String db) get the database name
java.lang.String	getDatabaseProductVersion(java.lang.String db) get the database version
static DBConnectionManager	getInstance() Returns the single instance, creating one if it's the first time this method is called.
java.util.Hashtable	getPools() get the pool names
java.lang.String	getUploadDir() get the upload directory
void	release() Closes all open connections and deregisters all drivers.
java.lang.String	sqlFalse(java.lang.String db) Database-dependent representation of a 'false' boolean value
java.lang.String	sqlToday(java.lang.String db) Database-dependent SQL operator to insert today's date
java.lang.String	sqlTrue(java.lang.String db) Database-dependent representation of a 'true' boolean value
java.lang.String	sqlUppercaseOperator(java.lang.String db) Database-dependent SQL operator to uppercase a value

Methods inherited from class java.lang.Object

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

Field Detail

UNKNOWN

public static final int UNKNOWN

Constants representing different RDBMSs

See Also:

Constant Field Values

POSTGRES

public static final int POSTGRES

See Also:

Constant Field Values

ACCESS

public static final int ACCESS

See Also:

Constant Field Values

MYSQL

public static final int MYSQL

See Also:

Constant Field Values

Method Detail

getInstance

public static DBConnectionManager getInstance()

Returns the single instance, creating one if it's the first time this method is called.

Returns:

DBConnectionManager The single instance.

freeConnection

public void freeConnection(java.lang.String name,
                           java.sql.Connection con)

Returns a connection to the named pool.

Parameters:

name - The pool name as defined in the properties file

con - The Connection

getPools

public java.util.Hashtable getPools()

get the pool names

Returns:

Enumeration A list of names

getUploadDir

public java.lang.String getUploadDir()

get the upload directory

getDatabaseEngineType

public int getDatabaseEngineType(java.lang.String db)

get the database name

Parameters:

db - The name of the database

Returns:

int A list of names

getDatabaseProductVersion

public java.lang.String getDatabaseProductVersion(java.lang.String db)
                                           throws java.lang.Exception

get the database version

Throws:

java.lang.Exception

getConnection

public java.sql.Connection getConnection(java.lang.String callingClass,
                                         java.lang.String name)

Returns an open connection. If no one is available, and the max number of connections has not been reached, a new connection is created.

Parameters:

name - The pool name as defined in the properties file

Returns:

Connection The connection or null

getConnection

public java.sql.Connection getConnection(java.lang.String callingClass,
                                         java.lang.String name,
                                         long time)

Returns an open connection. If no one is available, and the max number of connections has not been reached, a new connection is created. If the max number has been reached, waits until one is available or the specified time has elapsed.

Parameters:

name - The pool name as defined in the properties file

time - The number of milliseconds to wait

Returns:

Connection The connection or null

release

public void release()

Closes all open connections and deregisters all drivers.

sqlUppercaseOperator

public java.lang.String sqlUppercaseOperator(java.lang.String db)
                                      throws java.lang.Exception

Database-dependent SQL operator to uppercase a value

Parameters:

db - The name of the database

Returns:

Connection The connection or null

Throws:

java.lang.Exception

sqlToday

public java.lang.String sqlToday(java.lang.String db)
                          throws java.lang.Exception

Database-dependent SQL operator to insert today's date

Throws:

java.lang.Exception

sqlTrue

public java.lang.String sqlTrue(java.lang.String db)

Database-dependent representation of a 'true' boolean value

sqlFalse

public java.lang.String sqlFalse(java.lang.String db)

Database-dependent representation of a 'false' boolean value