Java Mongodb Date ObjectId 互轉

		////////////ObjectId 轉 Date
		///ObjectId前8位是日期，轉成10進制,乘以1000
		long time = Integer.parseInt((ObjectId.toString()).substring(0, 8), 16) * 1000L;
		Date date = new Date(time);

		logger.debug(date.toString());
		
		/////////Date 轉 ObjectId
		Date date2=new Date();
		ObjectId objectId=new ObjectId(date2);
		
		logger.debug(objectId.toString());