org.xmlBlaster.contrib.dbwatcher
Interface I_ChangeListener

All Superinterfaces:

java.util.EventListener

All Known Implementing Classes:

DbWatcher

public interface I_ChangeListener

extends java.util.EventListener

Interface which reports back changes to the observed data. The change can be a pure, empty event or it can contain all details already depending on the implementing notifier.

Author:

Marcel Ruff

Method Summary

void	hasChanged(ChangeEvent changeEvent) Is called for every data source changed.
int	publishMessagesFromStmt(java.lang.String stmt, boolean useGroupCol, ChangeEvent changeEvent, java.sql.Connection conn) Does a SQL query with stmt and sends all ResultSets to I_ChangePublisher.
void	shutdown() Cleanup resources.

Method Detail

hasChanged

public void hasChanged(ChangeEvent changeEvent)

Is called for every data source changed.

Parameters:

changeEvent - Transports all needed information about the change

publishMessagesFromStmt

public int publishMessagesFromStmt(java.lang.String stmt,
                                   boolean useGroupCol,
                                   ChangeEvent changeEvent,
                                   java.sql.Connection conn)
                            throws java.lang.Exception

Does a SQL query with stmt and sends all ResultSets to I_ChangePublisher.

The messages are formatted by the configured I_DataConverter plugin.

Note: This is a common convenienve function, in a future refactoring we should have this method in a separate interface.

Parameters:

stmt - The SQL query string (with/without grouping)

useGroupCol - If true we send a message for each ChangeEvent.getGroupColName() change

changeEvent - The reason to send

conn - The JDBC connection, if null we get one ourself in auto commit mode

Returns:

The number of changes detected TODO! (currently returns -1)

Throws:

java.lang.Exception - of any type

shutdown

public void shutdown()
              throws java.lang.Exception

Cleanup resources.

Throws:

java.lang.Exception - Can be of any type as implemented by plugin