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
isSchemaSupported = metaDataProvider.isSchemaSupported( );
			}
		}
		catch ( Exception e )
		{
			ExceptionHandler.showException( this.getShell( ),
					JdbcPlugin.getResourceString( "exceptionHandler.title.error" ),
					e.getLocalizedMessage( ),
					e );
		}
	}
	/**
	 * initial dataset control
	 * 
	 */
	private void initializeControl( )
	{
		isPageInitialization = true;
		
		initializeSchemaPrefetchConfig( );
		
		DEFAULT_MESSAGE = JdbcPlugin.getResourceString( "dataset.new.query" );
		setMessage( DEFAULT_MESSAGE, IMessageProvider.NONE );
		refreshPage( );
		prepareUI( );
	}
	/**
	 * 
	 *
	 */