private String calCost(Timestamp startTime, Timestamp endTime,
			long startId, long endId, ArrayList<RealTimePrice> priceList)
			throws InterruptedException, ExecutionException {
		List<Future<String>> list = new ArrayList<Future<String>>();
		long length = (endId - startId) / 10, min = startId, max = startId
				+ length;
		int i = 1;
		GetThreadPool queryThreadPoolWithBigGroup = new GetThreadPool(2);
		for (; i <= 10; i++) {
			if (i != 10) {
				list.add(queryThreadPoolWithBigGroup.getExecutorService()
						.submit(new CalculationCostWithSmallGroup(min, max,
								startTime, endTime, priceList)));
				min = max;
				max = min + length;
			} else {
				list.add(queryThreadPoolWithBigGroup.getExecutorService()
						.submit(new CalculationCostWithSmallGroup(min,
								endId + 1, startTime, endTime, priceList)));
			}
		}
		for (Future<String> future : list) {
			future.get();
		}
		System.out.println("finished");
		return "finished";
	}