Bug 199021 Error message pops up several times when click an invalid dataset
Description: There is a sqlserver datasource and dataset, remove the jtds driver to let the dataset invalid. Double click on the dataset, the error message will pop up serveral times. Build version:2.2.0.v20070807-0630 Steps to reproduce: 1. Create a sqlserver datasource and dataset. 2. Remove the jtds driver, and the dataset will be invalid. 3. Double click on the dataset. Expect result: Error message pops up once to indicate the problem. Actual result: Error message pops up serveral times.
data/org.eclipse.birt.report.data.oda.jdbc.ui/src/org/eclipse/birt/report/data/oda/jdbc/ui/editors/SQLDataSetEditorPage.java
catch ( SQLException e )
			{
				logger.log( Level.FINE, e.getMessage( ), e );
			}
		}
		if ( hasNonSystemTable )
		{
			return true;
		}
		else
		{
			return false;
		}
	}
	/**
	 * Sets the Root Element of the Available Data Sources This is usually the
	 * Name of the Catalog of the Database
	 */
	protected void setRootElement( )
	{
		rootNode = new TreeItem( availableDbObjectsTree, SWT.NONE );
		rootNode.setImage( dataBaseImage );
		DataSourceDesign dataSourceHandle = this.getDataSetDesign( )
				.getDataSourceDesign( );
		rootNode.setText( dataSourceHandle.getName( ) );
		rootNode.setData( new DbObject( "", DbObject.ROOT_NODE_TYPE ) );
	}
	/**
	 * Remove all available db objects
	 *