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
{
	private Scriptable 				sharedScope;
	private ExpressionCompiler		compiler;
	
	private HashMap					dataSources = new HashMap();
	
	
	private HashMap					dataSetDesigns = new HashMap();
	
	
	private Scriptable				dataSourcesJSObject;
	
	private DataEngineContext context;
	
	protected static Logger logger = Logger.getLogger( DataEngineImpl.class.getName( ) );
	/**
	 * Constructor to specify the DataEngine Context to use by the Data Engine
	 * for all related ReportQuery processing.
	 * 
	 * @param context
	 *            scope of Context: The global JavaScript scope shared by all
	 *            runtime components within a report sesssion. If this parameter
	 *            is null, a new standard top level scope will be created and
	 *            used.
	 */
	public DataEngineImpl( DataEngineContext context )
	{
		assert context != null;
		
		logger.entering( DataEngineImpl.class.getName( ),