Package de.aristaflow.adept2.base.dbaccess

Interface JDBCDataSource

All Superinterfaces:

ADEPT2Service

public interface JDBCDataSource
extends ADEPT2Service

Represents a JDBC data source. It only provides a method to retrieve a connection to this data source.

Author:

Patrick Schmidt

Method Summary

Modifier and Type	Method	Description
ExtendedConnection	getConnection(boolean readOnly)	Gets a read-only or writable connection to this data source.
ExtendedConnection	getConnection(boolean readOnly, int isolation)	Gets a read-only or writable connection to this data source having the designated isolation level.
ExtendedConnection	getIteratorConnection()	Similar to getConnection(boolean) but the returned connection is intended to be used in a potentially long-living RemoteIterator wrapping a result set.
void	registerRemoteIterator(RemoteIterator<?> iterator, long aliveTime)	Registers the designated result set remote iterator to drop it after the designated alive time has elapsed.

Methods inherited from interface de.aristaflow.adept2.base.service.ADEPT2Service

getLocalUris, getRelease, getRuntimeRequiredServices, getServiceInstanceName, getStartupRequiredServices, getURIs, init, ping, preShutdown, shutdown, start

Method Detail

getConnection

ExtendedConnection getConnection(boolean readOnly)
                          throws SQLException

Gets a read-only or writable connection to this data source. This will have the default isolation level of the underlying database system.
Do not forget to close the connection after being done using it! Note that autocommit will be disabled per default.

Please be aware that the maximum number of concurrent open connections may be limited, e.g. if connections are pooled and a connection limit is enforced. I.e. this method will block until a connection is available. So when more than one connection is acquired during an operation (concurrently) - within the same method or in another called method - and the number of available connections is exhausted, a deadlock may occur.

Parameters:

readOnly - Whether the connection should be read-only, thus allowing more concurrency.

Returns:

A connection to this data source.

Throws:

SQLException - If there are problems creating the connection, an SQLException will be thrown.

getConnection

ExtendedConnection getConnection(boolean readOnly,
                                 int isolation)
                          throws SQLException

Gets a read-only or writable connection to this data source having the designated isolation level. Please take care to only request isolation levels that are supported by the underlying database system.
Do not forget to close the connection after being done using it! Note that autocommit will be disabled per default.

Please be aware that the maximum number of concurrent open connections may be limited, e.g. if connections are pooled and a connection limit is enforced. I.e. this method will block until a connection is available. So when more than one connection is acquired during an operation (concurrently) - within the same method or in another called method - and the number of available connections is exhausted, a deadlock may occur.

Parameters:

readOnly - Whether the connection should be read-only, thus allowing more concurrency.

isolation - The isolation level for the connection allowing more or less concurrency.

Returns:

A connection to this data source.

Throws:

SQLException - If there are problems creating the connection, this includes requesting an isolation level that is not supported by the underlying database system, an SQLException will be thrown.

getIteratorConnection

ExtendedConnection getIteratorConnection()
                                  throws SQLException

Similar to getConnection(boolean) but the returned connection is intended to be used in a potentially long-living RemoteIterator wrapping a result set. The connections are read-only and have Connection.TRANSACTION_READ_COMMITTED.

Implementations may manage these connection differently, e.g. in a separate pool, so long-living iterators don't dry out other operations.

Returns:

a connection to this data source solely intended for use in ResultSetRemoteIterators

Throws:

SQLException - if no connection could be acquired

registerRemoteIterator

void registerRemoteIterator(RemoteIterator<?> iterator,
                            long aliveTime)

Registers the designated result set remote iterator to drop it after the designated alive time has elapsed. The iterator can be safely dropped beforehand.

Parameters:

iterator - The iterator to drop after its alive time has elapsed.

aliveTime - The time in milliseconds the designated iterator can be active without being forced to be dropped.