planetj.database
Interface IDataEngineListener

All Superinterfaces:

EventListener

public interface IDataEngineListener

extends EventListener

DataEngineListeners register with SQLContext objects, and are alerted whenever that SQLContext is used in a DataEngine operation.

Field Summary

static int	SQL_EXECUTE
static int	SQL_QUERY
static int	SQL_UPDATE

Method Summary

void	exceptionOccurred(SQLContext context, CMException cme, int sqlOperation) This method is invoked when a SQLContext object with which this listener is registered is used in a DataEngine operation which throws an exception.
void	executionCompleted(SQLContext context) Invoked whenever a SQLContext to which this object is listening is used to execute a SQL statement.
void	queryCompleted(SQLContext context, RowCollection rc) This method is invoked when a SQLContext object with which this listener is registered is used in a DataEngine query.
void	updateCompleted(SQLContext context, int updated) Invoked whenever a SQLContext to which this object is listening is used to update a database.

Field Detail

SQL_QUERY

public static final int SQL_QUERY

See Also:

Constant Field Values

SQL_UPDATE

public static final int SQL_UPDATE

See Also:

Constant Field Values

SQL_EXECUTE

public static final int SQL_EXECUTE

See Also:

Constant Field Values

Method Detail

exceptionOccurred

public void exceptionOccurred(SQLContext context,
                              CMException cme,
                              int sqlOperation)

This method is invoked when a SQLContext object with which this listener is registered is used in a DataEngine operation which throws an exception.

Parameters:

context - The SQLContext with which this listener was registered. The connection which was in use when the exception was thrown has been released; any future operations done with the SQLContext object will take a (possible different) connection from the DatabaseManager.

cme - The exception that was thrown.

sqlOperation - The type of operation that caused the exception. This will be one of the constants defined in the DataEngineListener interface.

executionCompleted

public void executionCompleted(SQLContext context)

Invoked whenever a SQLContext to which this object is listening is used to execute a SQL statement.

Parameters:

context - The SQLContext with which this listener was registered. The connection which was used in the statement is still contained in the SQLContext. If this connection was set in the SQLContext with the setConnection() method, then it needs to be freed (possibly in this method). If the connection was automatically retrieved from the system alias (specified with the setSystemAlias() method), then it is not necessary to free it.

queryCompleted

public void queryCompleted(SQLContext context,
                           RowCollection rc)

This method is invoked when a SQLContext object with which this listener is registered is used in a DataEngine query. If the query was not run in a background thread then this method will be invoked before the getRows() method returns.

Parameters:

context - The SQLContext with which this listener was registered. If the connection was specifically set in the SQLContext with the setConnection() method, then it is still present in the SQLContext. Otherwise, the connection which ran the query has already been returned to the pool.

rc - The RowCollection resulting from the query.

updateCompleted

public void updateCompleted(SQLContext context,
                            int updated)

Invoked whenever a SQLContext to which this object is listening is used to update a database.

Parameters:

context - The SQLContext with which this listener was registered. The connection which was used in the statement is still contained in the SQLContext. If this connection was set in the SQLContext with the setConnection() method, then it needs to be freed (possibly in this method). If the connection was automatically retrieved from the system alias (specified with the setSystemAlias() method), then it is not necessary to free it.

updated - The number of rows in the database which were altered as a result of the update