Elastic Search 聚合分析操作

// 复杂搜索
SearchResponse response = client.prepareSearch("resource")
        .setTypes("label")
        .setQuery(QueryBuilders.matchQuery("title", "App版本升级"))
        .setPostFilter(QueryBuilders.rangeQuery("priority").from(4).to(9))
        .setFrom(0)
        .setSize(2)
        .get();
SearchHit[] searchHits = response.getHits().getHits();
for (SearchHit searchHit : searchHits) {
    System.out.println(searchHit.getSourceAsString());
}

// 聚合操作
SearchResponse searchResponse = client.prepareSearch("company")
        .addAggregation(AggregationBuilders.terms("group_by_country").field("country")
                .subAggregation(AggregationBuilders
                        .dateHistogram("group_by_join_date")
                        .field("join_date")
                        .dateHistogramInterval(DateHistogramInterval.YEAR)
                        .subAggregation(AggregationBuilders.avg("avg_salary").field("salary")))
        )
        .execute().actionGet();

Map<String, Aggregation> aggrMap = searchResponse.getAggregations().asMap();

StringTerms groupByCountry = (StringTerms) aggrMap.get("group_by_country");
Iterator<StringTerms.Bucket> groupByCountryBucketIterator = groupByCountry.getBuckets().iterator();
while(groupByCountryBucketIterator.hasNext()) {
    StringTerms.Bucket groupByCountryBucket = groupByCountryBucketIterator.next();
    System.out.println(groupByCountryBucket.getKey() + ":" + groupByCountryBucket.getDocCount());

    Histogram groupByJoinDate = (Histogram) groupByCountryBucket.getAggregations().asMap().get("group_by_join_date");
    Iterator<? extends Histogram.Bucket> groupByJoinDateBucketIterator = groupByJoinDate.getBuckets().iterator();
    while(groupByJoinDateBucketIterator.hasNext()) {
        org.elasticsearch.search.aggregations.bucket.histogram.Histogram.Bucket groupByJoinDateBucket = groupByJoinDateBucketIterator.next();
        System.out.println(groupByJoinDateBucket.getKey() + ":" +groupByJoinDateBucket.getDocCount());

        Avg avg = (Avg) groupByJoinDateBucket.getAggregations().asMap().get("avg_salary");
        System.out.println(avg.getValue());
    }
}