aws-sdk javaでAWS課金情報を取得する

private final static String ACCESS_KEY = "YYYYYYYYYYY";
private final static String SECRET_ACCESS_KEY = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";

AWSCredentials awsCredentials = new BasicAWSCredentials(ACCESS_KEY,
     SECRET_ACCESS_KEY);
AmazonCloudWatchClient awsClient = new AmazonCloudWatchClient(
     awsCredentials);

String[] accountIds = { "xxxxxxxxxxx", "yyyyyyyyyyyyy", "zzzzzzzzzzzzzzz" };
double currentBillingValue = 0;
for (String accountId : accountIds) {

 ListMetricsRequest request = new ListMetricsRequest();
 ListMetricsResult list = awsClient.listMetrics(request);

 GetMetricStatisticsRequest getMetricStatisticsRequest = new GetMetricStatisticsRequest();
 Date date = new Date();
 getMetricStatisticsRequest.setStartTime(new Date(date.getTime()
     - (24 * 3600 * 1 * 1000)));
 getMetricStatisticsRequest.setEndTime(new Date());
 getMetricStatisticsRequest.setMetricName("EstimatedCharges");
 getMetricStatisticsRequest.setNamespace("AWS/Billing");
 getMetricStatisticsRequest.setPeriod(86400);

 Collection<Dimension> dimensions = new ArrayList<Dimension>();
 Dimension accountDimension = new Dimension();
 accountDimension.setName("LinkedAccount");
 accountDimension.setValue(accountId);
 dimensions.add(accountDimension);

 Dimension currenctDimension = new Dimension();
 currenctDimension.setName("Currency");
 currenctDimension.setValue("USD");
 dimensions.add(currenctDimension);

 getMetricStatisticsRequest.setDimensions(dimensions);

 Collection<String> statistics = new ArrayList<String>();
 statistics.add("Maximum");
 getMetricStatisticsRequest.setStatistics(statistics);
 awsClient.getMetricStatistics(getMetricStatisticsRequest);
 GetMetricStatisticsResult getMetricStatisticsResult = awsClient
     .getMetricStatistics(getMetricStatisticsRequest);
 List<Datapoint> dataPoints = getMetricStatisticsResult
     .getDatapoints();
 Collections.sort(dataPoints, new DataPointComparator());
 if (dataPoints.size() > 0) {
   currentBillingValue += dataPoints.get(dataPoints.size() - 1).getMaximum();
 }