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/executor/DataSource.java
/**
     * Closes a PreparedStatement returned by the prepareStatement call. Frees the associated
     * ODA Connection and make it available for new statements. 
     */
    synchronized void closeStatement ( PreparedStatement stmt )
    {
    	assert stmt != null;
    	
    	CacheConnection conn = (CacheConnection) statementMap.remove( stmt );
    	if ( conn == null )
    	{
    		
    		logger.logp( Level.WARNING, className, "closeStatement",
    				"statement not found");
    		
    	}
    	else
    	{
    		-- conn.currentStatements;
    		if ( conn.currentStatements < 0 )
        		logger.warning( DataSource.class.getName() + ".closeStatement: negative statement count for connection.");
    		
    		
    	}
    	
    	try
		{
    		stmt.close();
		}
        catch ( DataException e )