Bug 136141 Prepared statements not properly cleaned up.
After designing a JDBC query in a report design, I opened the DataSetEditor and choose "Preview Results". There are a number of warnings that came up in the Console indicating there are prepared statements not properly managed or cleaned up. Apr 11, 2006 8:23:04 AM org.eclipse.birt.data.engine.executor.DataSource close WARNING: 1 statements still active. Apr 11, 2006 8:23:05 AM org.eclipse.birt.data.engine.executor.DataSource closeStatement WARNING: statement not found Tracing down the problem a little further, the root cause of the problem is because the DataSourceQuery (in data.engine.executor) is trying to close a dangling reference of a PreparedStatement. The PreparedStatement has been previously dropped from the statementMap of the DataSource when the DataSource.close() was called. But DataSourceQuery is still holding on to a reference of it. The sequence is as follows: 1) DataSourceQuery prepares a statement. This in turn makes DataSource prepare a statement, and creates a PreparedStatement object, adds it to the statementMap. 2) During DataEngineImpl.defineDataSource(), the existing DataSource is closed, replaced by the supplied DataSourceDesign. The DataSource still have statements in its map. And a warning is logged indicating this is a resource leak. It then cleans the statementMap and closes all its open connections. 3) When DataSourceQuery tries to close the dangling statement, it cannot find it. It logs a message "Statement not found". Then, it still proceeds to close it.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/DataEngineImpl.java
* on a data set that uses such data source connection.
	 * The data source identified by name, should be one referenced 
	 * in one or more of the previously prepared ReportQuery.  
	 * Otherwise, it would simply return with no-op.
	 * <br>
	 * In BIRT Release 1, this method will likely be called by FPE 
	 * at the end of a report generation.
	 * @param	dataSourceName	The name of a data source connection.
	 */
	public void closeDataSource( String dataSourceName ) throws DataException
	{
		logger.entering( "DataEngineImpl",
				"closeDataSource",
				dataSourceName );
		if ( dataSources == null )
		{
			IllegalStateException e = new IllegalStateException( "DataEngine has been shutdown" );
			logger.logp( Level.WARNING,
					DataEngineImpl.class.getName( ),
					"closeDataSource",
					"DataEngine has been shutdown",
					e );
			throw e;
		}
		logger.logp( Level.FINE,
				DataEngineImpl.class.getName( ),
				"closeDataSource",
				"Close DataSource :" + dataSourceName );
		DataSourceRuntime ds = getDataSourceRuntime( dataSourceName );
		if ( ds != null )