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. Manages a "primary" and (optionally) a "secondary" ConnectionFactory. When caching is enabled it maintains caches of the allocated ManagedConnection per ExecutionContext (an EC can have a single ManagedConnection per ConnectionFactory at any time).

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 on a read-only operation, or when running non-transactional, or to get schema information.

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
void	close() Method to close the connection manager.
void	closeAllConnections(ExecutionContext ec) Method to close all pooled connections for the specified ExecutionContext.
void	disableConnectionCaching() Disable binding objects to "ExecutionContext" references, so automatically disables the connection caching.
ManagedConnection	getConnection(boolean primary, ExecutionContext ec, Transaction txn) Accessor for a connection from the specified factory, for the specified ExecutionContext dependent on whether the connection will be enlisted.
default ManagedConnection	getConnection(ExecutionContext ec) Accessor for a connection for the specified ExecutionContext.
ManagedConnection	getConnection(ExecutionContext ec, Map options) Accessor for a connection for the specified ExecutionContext.
ManagedConnection	getConnection(int isolationLevel) Accessor for a connection for the specified transaction isolation level.

Method Detail

close

void close()

Method to close the connection manager. This will close all open connections.

disableConnectionCaching

void disableConnectionCaching()

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

getConnection

default ManagedConnection getConnection(ExecutionContext ec)

Accessor for a connection for the specified ExecutionContext. If there is an active transaction, a connection from the primary connection factory will be returned. If there is no active transaction, a connection from the secondary connection factory will be returned (unless the user has specified to just use the primary).

Parameters:

ec - execution context

Returns:

The ManagedConnection

Throws:

NucleusException - Thrown if an error occurs getting the connection

getConnection

ManagedConnection getConnection(ExecutionContext ec,
                                Map options)

Accessor for a connection for the specified ExecutionContext. If there is an active transaction, a connection from the primary connection factory will be returned. If there is no active transaction, a connection from the secondary connection factory will be returned (unless the user has specified to just use the primary).

Parameters:

ec - execution context

options - connection options

Returns:

The ManagedConnection

Throws:

NucleusException - Thrown if an error occurs getting the connection

getConnection

ManagedConnection getConnection(int isolationLevel)

Accessor for a connection for the specified transaction isolation level. This is used for schema and sequence access operations.

Parameters:

isolationLevel - Isolation level (-1 implies use the default for the datastore).

Returns:

The ManagedConnection

Throws:

NucleusException - Thrown if an error occurs getting the connection

getConnection

ManagedConnection getConnection(boolean primary,
                                ExecutionContext ec,
                                Transaction txn)

Accessor for a connection from the specified factory, for the specified ExecutionContext dependent on whether the connection will be enlisted.

Parameters:

primary - Whether to take use the "primary" connection factory, otherwise takes the "secondary"

ec - ExecutionContext

txn - The Transaction

Returns:

The ManagedConnection

closeAllConnections

void closeAllConnections(ExecutionContext ec)

Method to close all pooled connections for the specified ExecutionContext.

Parameters:

ec - The ExecutionContext