准备数据来自elasticsearch系统学习笔记9-聚合分析 Aggregations（补充1）
基本流程
RestHighLevelClient restHighLevelClient = getRestHighLevelClient();
try {
// 索引名
String indexName = "cars_transactions";
// 构建聚合语句
// 创建terms桶聚合 , 聚合名字 colors_agg , 根据 color 分组
TermsAggregationBuilder aggregationBuilder = AggregationBuilders.terms("colors_agg").field("color");
// 嵌套聚合 设置 avg 指标聚合，聚合名字 avg_price, 字段 price，计算平均价格
aggregationBuilder.subAggregation(AggregationBuilders.avg("avg_price").field("price"));
// 构建 SearchSourceBuilder
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.query(QueryBuilders.matchAllQuery());
sourceBuilder.size(0);
sourceBuilder.aggregation(aggregationBuilder); // 聚合
// 构建 searchRequest
SearchRequest searchRequest = new SearchRequest();
searchRequest.source(sourceBuilder);
searchRequest.indices(indexName);
// 执行请求
SearchResponse searchResponse = restHighLevelClient.search(searchRequest);
// 遍历查询结果
listAggregations(searchResponse);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (restHighLevelClient != null) {
restHighLevelClient.close();
}
}
public static void listAggregations(SearchResponse searchResponse) {
// 处理聚合查询结果
Aggregations aggregations = searchResponse.getAggregations();
// 根据by_shop名字查询terms聚合结果
Terms byShopAggregation = aggregations.get("colors_agg");
// 遍历terms聚合结果
for (Terms.Bucket bucket : byShopAggregation.getBuckets()) {
// 因为是根据shop_id分组，因此可以直接将桶的key转换成int类型
String color = bucket.getKeyAsString();
long colorCount = bucket.getDocCount();
System.out.print("颜色 " + color + "\n数量 : " + colorCount);
// 根据avg_price聚合名字，获取嵌套聚合结果
Avg avg = bucket.getAggregations().get("avg_price");
// 获取平均价格
double avgPrice = avg.getValue();
System.out.println(" ; 平均价格 : " + avgPrice);
}
}
指标
- 总数和总和
ValueCountAggregationBuilder valueCountAggregationBuilder = AggregationBuilders.count("count_orders").field("order_id"); SumAggregationBuilder sumAggregationBuilder = AggregationBuilders.sum("total_sale").field("price"); // 设置聚合查询,可以设置多个聚合查询条件，只要聚合查询命名不同就行 sourceBuilder.aggregation(valueCountAggregationBuilder); sourceBuilder.aggregation(sumAggregationBuilder); // 处理结果 ValueCount valueCount = aggregations.get("count_orders"); Sum totalPrice = aggregations.get("total_sale"); - 最大最小值
MaxAggregationBuilder maxAggregationBuilder = AggregationBuilders.max("max_price").field("price");
MinAggregationBuilder minAggregationBuilder = AggregationBuilders.min("min_price").field("price");
Max maxPrice = aggregations.get("max_price");
Min minPrice = aggregations.get("min_price");
桶
- terms 分桶
TermsAggregationBuilder byShop = AggregationBuilders.terms("by_shop").field("shop_id"); - 等等
