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/provider/JdbcMetaDataProvider.java
while ( columnsRs.next( ) )
			{
				
				 
				Column column = new Column( );
				column.setSchemaName( columnsRs.getString( "TABLE_SCHEM" ) );
				column.setTableName( columnsRs.getString( "TABLE_NAME" ) );
				column.setName( columnsRs.getString( "COLUMN_NAME" ) );
				column.setDbType( columnsRs.getString( "TYPE_NAME" ) );
				columnList.add( column );
			}
		}
		catch ( SQLException e )
		{
			logger.log( Level.FINE, e.getMessage( ), e );
		}
		return columnList;
	}
	/**
	 * @param catalog
	 * @param schemaPattern
	 * @param tableNamePattern
	 * @param columnNamePattern
	 * @return
	 * @throws SQLException
	 */
	private void resetMetadata( ) throws SQLException
	{
		jdbcConnection = DriverLoader.getConnection( driverClass,
				url,