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
/*
     * @see org.eclipse.birt.data.engine.odi.IDataSource#open()
     */
    public void open( ) throws DataException
	{
		
		if ( isOpen( ) )
			return;
		
		
		
		if ( driverName == null || driverName.length( ) == 0 )
			return;
		
		newConnection( );
	}
    
    /**
     * Opens a new Connection and add it to the pool
     * 
     * @return
     * @throws DataException
     */
    private CacheConnection newConnection() throws DataException
    {
    	CacheConnection conn = new CacheConnection();
    	conn.odaConn = ConnectionManager.getInstance().openConnection( 
    			driverName, connectionProps, appContext );
    	int max = conn.odaConn.getMaxQueries();
    	if ( max != 0 )