Bug 136553 [regression]Preview error when set invalid group interval.
Description: Preview error when set invalid group interval. Steps to reproduce: 1. Insert a table 2. Add a group on number column, set interval to Year,1 3. Preview 4. Edit group on string column set interval to Prefix,1 5. Preview Expected result: Error msg about invalid group interval. Actual result: Error happened while running the report
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/data/dte/DataGenerationEngine.java
dos = null;
		}
		dteEngine.shutdown( );
	}
	/**
	 * save the metadata into the streams.
	 * 
	 * @param key
	 */
	private void storeDteMetaInfo( String pRsetId, long rowId, String queryId,
			String rsetId )
	{
		if ( null != dos )
		{
			try
			{
				IOUtil.writeString( dos, pRsetId );
				IOUtil.writeLong( dos, rowId );
				IOUtil.writeString( dos, queryId );
				IOUtil.writeString( dos, rsetId );
			}
			catch ( IOException e )
			{
				logger.log( Level.SEVERE, e.getMessage( ) );
				e.printStackTrace( );
			}
		}
	}
}