de.zib.scalaris
Class ConnectionPool

java.lang.Object
  de.zib.scalaris.ConnectionPool

public class ConnectionPool
extends Object

Implements a simple (thread-safe) connection pool for Scalaris connections.

Since:

3.7

Version:

3.7

Author:

Nico Kruber, kruber@zib.de

Constructor Summary

ConnectionPool(ConnectionFactory cFactory, int maxConnections)
Creates a new connection pool.

Method Summary

void	closeAll() Closes all available pooled connections.
void	closeAllBut(Collection<PeerNode> remainingNodes) Closes all available pooled connections to any node not in the given collection.
Connection	getConnection() Gets a connection from the pool.
Connection	getConnection(long timeout) Tries to get a valid connection from the pool waiting at most timeout milliseconds.
ConnectionFactory	getConnectionFactory() Gets the connection factory used by the pool.
void	releaseConnection(Connection conn) Puts the given connection back into the pool.

Methods inherited from class java.lang.Object

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

Constructor Detail

ConnectionPool

public ConnectionPool(ConnectionFactory cFactory,
                      int maxConnections)

Creates a new connection pool.

Parameters:

cFactory - the connection factory to use to create new connections

maxConnections - the maximum number of connections (0 for no limit)

Method Detail

getConnection

public Connection getConnection()
                         throws ConnectionException

Gets a connection from the pool. Creates a new connection if necessary. Returns null if the maximum number of connections has already been hit.

Returns:

a connection to Scalaris or null if the maximum number of connections has been hit

Throws:

ConnectionException - if creating the connection fails

getConnection

public Connection getConnection(long timeout)
                         throws ConnectionException

Tries to get a valid connection from the pool waiting at most timeout milliseconds. Creates a new connection if necessary and the maximum number of connections has not been hit yet. If the timeout is hit and no connection is available, null is returned.

Parameters:

timeout - number of milliseconds to wait at most for a valid connection to appear (0 to wait forever)

Returns:

a connection to Scalaris or null if the timeout has been hit

Throws:

ConnectionException - if creating the connection fails

releaseConnection

public void releaseConnection(Connection conn)

Puts the given connection back into the pool.

Parameters:

conn - the connection to release

closeAll

public void closeAll()

Closes all available pooled connections. NOTE: This does not include any checked out connections!

closeAllBut

public void closeAllBut(Collection<PeerNode> remainingNodes)

Closes all available pooled connections to any node not in the given collection. NOTE: This does not include any checked out connections!

Parameters:

remainingNodes - a set of nodes to which connections should remain (fast access to Collection.contains(Object) is preferable, e.g. use Set)

getConnectionFactory

public ConnectionFactory getConnectionFactory()

Gets the connection factory used by the pool.

Returns:

the connection factory