org.w3c.tools.jdbc
Class ConnectionManager

java.lang.Object
  org.w3c.tools.jdbc.ConnectionManager

All Implemented Interfaces:

PropertyMonitoring

public class ConnectionManager
extends java.lang.Object
implements PropertyMonitoring

Field Summary

protected java.util.Comparator	conn_comparator
protected int	conn_count
protected int	conn_max
protected int	conn2free
protected LRUList	connectionsLru The LRU list of idle connections.
static boolean	debug
protected int	state
static int	STATE_CHANGED
static int	STATE_UNCHANGED
protected java.util.LinkedList	usedConnections The LRU list of used connection
static long	WAIT_TIMEOUT

Method Summary

protected JdbcConnection	allocateConnection(JdbcServer server) Connections management - Allocate a new connection for this server.
protected void	deleteConnection(JdbcConnection conn)
protected void	freeConnections() PANIC, we need to close some used connection.
protected JdbcConnection	getConnection(JdbcServer server) Get a connection to the given server.
static ConnectionManager	getManager()
static ConnectionManager	getManager(java.util.Properties p) Get an instance of the Jdbc manager.
protected boolean	negotiateConnection(JdbcServer server)
protected void	notifyConnection(JdbcConnection conn) A new connection has just been created.
void	notifyIdle(JdbcConnection conn) The given connection can be reused, but is now idle.
void	notifyUse(JdbcConnection conn) The given connection is about to be used.
boolean	propertyChanged(java.lang.String name) PropertyMonitoring implementation.
protected void	waitForConnection(JdbcServer server) Wait for a connection to come up.

Methods inherited from class java.lang.Object

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

Field Detail

WAIT_TIMEOUT

public static final long WAIT_TIMEOUT

See Also:

Constant Field Values

debug

public static final boolean debug

See Also:

Constant Field Values

STATE_UNCHANGED

public static final int STATE_UNCHANGED

See Also:

Constant Field Values

STATE_CHANGED

public static final int STATE_CHANGED

See Also:

Constant Field Values

state

protected int state

conn_count

protected int conn_count

conn_max

protected int conn_max

conn2free

protected int conn2free

connectionsLru

protected LRUList connectionsLru

The LRU list of idle connections.

usedConnections

protected java.util.LinkedList usedConnections

The LRU list of used connection

conn_comparator

protected java.util.Comparator conn_comparator

Method Detail

propertyChanged

public boolean propertyChanged(java.lang.String name)

PropertyMonitoring implementation.

Specified by:

propertyChanged in interface PropertyMonitoring

Parameters:

name - The name of the property that changed.

Returns:

A boolean, if true, accept the new property value, otherwise, reject it and reset the property to its old value.

getConnection

protected JdbcConnection getConnection(JdbcServer server)

Get a connection to the given server.

Parameters:

server - the jdbc server.

Returns:

a JdbcConnection or null if there is no connection available.

freeConnections

protected void freeConnections()

PANIC, we need to close some used connection.

allocateConnection

protected JdbcConnection allocateConnection(JdbcServer server)

Connections management - Allocate a new connection for this server.

Parameters:

server - the JdbcServer

Returns:

a newly created connection or null

negotiateConnection

protected boolean negotiateConnection(JdbcServer server)

deleteConnection

protected void deleteConnection(JdbcConnection conn)

notifyConnection

protected void notifyConnection(JdbcConnection conn)

A new connection has just been created.

Parameters:

conn - the new connection

notifyUse

public void notifyUse(JdbcConnection conn)

The given connection is about to be used. Update our list of available servers.

Parameters:

conn - The idle connection.

notifyIdle

public void notifyIdle(JdbcConnection conn)

The given connection can be reused, but is now idle.

Parameters:

conn - The connection that is now idle.

waitForConnection

protected void waitForConnection(JdbcServer server)
                          throws java.lang.InterruptedException

Wait for a connection to come up.

Parameters:

server, - the target server.

Throws:

java.lang.InterruptedException - If interrupted..

getManager

public static ConnectionManager getManager(java.util.Properties p)

Get an instance of the Jdbc manager. This method returns an actual instance of the Jdbc manager. It may return different managers, if it decides to distribute the load on different managers (avoid the ConnectionManager being a bottleneck).

Returns:

An application wide instance of the Jdbc manager.

getManager

public static ConnectionManager getManager()