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
return metadata.connect( dataSourceDesign );
	}
	/**
	 *  Create Metadata Provider
	 */
	protected void createMetaDataProvider( )
	{
		if ( metaDataProvider == null )
		{
			metaDataProvider = new JdbcMetaDataProvider( null );
		}
	}
	/**
	 *  Initializes the Jdbc related information , used  by this page
	 * ( such as the Jdbc Connection , Catalog Name etc )
	 * @param curDataSourceHandle
	 *
	 */
	protected void resetJdbcInfo( DataSourceDesign curDataSourceDesign )
	{
		if ( metaDataProvider != null )
		{
			metaDataProvider.closeConnection( );
			metaDataProvider = null;
			createMetaDataProvider( );
			jdbcConnection = connectMetadataProvider( metaDataProvider,
					curDataSourceDesign );
			
			tableList = null;
			schemaList = null;