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
{
				ExceptionHandler.showException( PlatformUI.getWorkbench( )
						.getDisplay( )
						.getActiveShell( ),
						JdbcPlugin.getResourceString( "exceptionHandler.title.error" ),
						e.getLocalizedMessage( ),
						e );
			}
      	}
      
    	if(metaData == null)
    	{
    		return "";
    	}
    	
    	String databaseName = "";
    	try {
			databaseName =  metaData.getDatabaseProductName();
		} catch (SQLException e) {
			logger.log( Level.FINE, e.getMessage( ), e );
		}
		
		if(databaseName == null)
		{
			databaseName = "";
		}
		
		return databaseName;
    }
    /*