org.datanucleus.store.connection

Interface ConnectionManager

All Known Implementing Classes:

ConnectionManagerImpl

public interface ConnectionManager

Manager of connections for a StoreManager, allowing ManagedConnection pooling, enlistment in transaction. The pool caches one connection per ExecutionContext. The allocateConnection method can create connections and enlist them (like most normal persistence operations need) or create a connection and return it without enlisting it into a transaction, for example the connections used to generate object identity, create the database schema or obtaining the schema metadata. The closeAllConnections method is typically called when the owning object (ExecutionContext) is being closed giving us chance to close all retained connections for that ExecutionContext.

Connections can be locked per ExecutionContext basis. Locking of connections is used to handle the connection over to the user application. A locked connection denies any further access to the datastore, until the user application unlock it.

Method Summary

Modifier and Type	Method and Description
ManagedConnection	allocateConnection(ConnectionFactory factory, ExecutionContext ec, Transaction tx, Map options) Allocate a connection using the specified factory (unless we already have one cached for the ExecutionContext).
void	closeAllConnections(ConnectionFactory factory, ExecutionContext ec) Method to close all pooled connections for the specified key of the specified factory.
void	disableConnectionPool() Disable binding objects to "ExecutionContext" references, so automatically disables the connection pooling
ConnectionFactory	lookupConnectionFactory(String name) Method to lookup a connection factory and create it if not yet existing.
void	registerConnectionFactory(String name, ConnectionFactory factory) Method to register a connection factory

Method Detail

lookupConnectionFactory

ConnectionFactory lookupConnectionFactory(String name)

Method to lookup a connection factory and create it if not yet existing.

Parameters:

name - The lookup name "e.g "jdbc/tx"

Returns:

The connection factory

registerConnectionFactory

void registerConnectionFactory(String name,
                               ConnectionFactory factory)

Method to register a connection factory

Parameters:

name - The lookup name "e.g "jdbc/tx"

factory - The connection factory

closeAllConnections

void closeAllConnections(ConnectionFactory factory,
                         ExecutionContext ec)

Method to close all pooled connections for the specified key of the specified factory.

Parameters:

factory - The factory

ec - The key in the pool

allocateConnection

ManagedConnection allocateConnection(ConnectionFactory factory,
                                     ExecutionContext ec,
                                     Transaction tx,
                                     Map options)

Allocate a connection using the specified factory (unless we already have one cached for the ExecutionContext).

Parameters:

factory - The ConnectionFactory to create any new connection with

ec - ExecutionContext that binds the connection during its lifetime (key in the pool)

tx - The transaction

options - Any overriding options for allocating the connection (e.g isolation) that override the transaction (default) options

Returns:

The ManagedConnection

disableConnectionPool

void disableConnectionPool()

Disable binding objects to "ExecutionContext" references, so automatically disables the connection pooling