本站于2023年9月4日。收到“大连君*****咨询有限公司”通知
说我们IIS7站长博客，有一篇博文用了他们的图片。
要求我们给他们一张图片6000元。要不然法院告我们
为避免不必要的麻烦，IIS7站长博客，全站内容图片下架、并积极应诉
博文内容全部不再显示，请需要相关资讯的站长朋友到必应搜索。谢谢！
另祝：版权碰瓷诈骗团伙，早日弃暗投明。
相关新闻：借版权之名、行诈骗之实，周某因犯诈骗罪被判处有期徒刑十一年六个月
叹！百花齐放的时代,渐行渐远!
通过聚合查询获取group by 后的数量
/**
* 获取key的个数
*
* @param key 要group by的字段名
* @param index 索引名称
* @return id的个数
*/
public static int getKeyCount(String key, String index) {
int count = 0;
TransportClient client = null;
try {
client = connectionPool.getConnection();
if (client == null) {
throw new Exception("没有获取到连接!");
}
SearchRequestBuilder search = client.prepareSearch(index);
//cardinality聚合查询，相当于groupby字段名
SearchResponse sr = search.addAggregation(AggregationBuilders.cardinality(key + "_count").field(key)).execute().actionGet();
//从返回数据提取id总数
Cardinality result = sr.getAggregations().get(key + "_count");
long value = result.getValue();
count = (int) value;
} catch (InterruptedException e) {
} catch (Exception e) {
logger.error("getKeyCount错误", e);
} finally {
connectionPool.releaseConnection(client);
}
return count;
}
获取group by后的所有key值
/**
* 获取所有key
*
* @param key 被group by的字段名
* @param index 索引名称
* @return 所有id
*/
public static List<String> getAllKey(String key, String index) {
int keyCount = getKeyCount(key, index);
List<String> strings = new ArrayList<>();
TransportClient client = null;
try {
client = connectionPool.getConnection();
if (client == null) {
throw new Exception("没有获取到数据库连接!");
}
SearchRequestBuilder searchRequestBuilder = client.prepareSearch(index);
//使用聚合，实现去重查询
SearchResponse searchResponse = searchRequestBuilder.
addAggregation(AggregationBuilders.terms("models").field(key).size(keyCount)).execute().actionGet();
Terms term = searchResponse.getAggregations().get("models");
List<? extends Terms.Bucket> buckets = term.getBuckets();
//遍历结果，提取出id
for (Terms.Bucket bucket : buckets) {
String keyAsString = bucket.getKeyAsString();
strings.add(keyAsString);
}
buckets.clear();
} catch (InterruptedException e) {
} catch (Exception e) {
logger.error("getAllKey错误", e);
} finally {
connectionPool.releaseConnection(client);
}
return strings;
}
