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说在前面：
Elasticsearch Java API 有四种实现方式：分别是 TransportClient、RestClient、Jest、Spring Data Elasticsearch。本文使用第一种方式，也就是 TransportClient 的方式进行实现。想要了解其他三种的方式可以看一下这篇文章：https://blog.csdn.net/qq_3331…
总结：
1、group 之后不能自动分页，需要手动设置；
2、size 需要指定，否则会出错。
group 之后分页、排序实现
需要手动截取分页对应范围内的数据。
比如：这里
倒序，获取到数据集的第 (currentPage-1) limit 到 currentPage limit 条记录；
升序，获取到数据集的 第 buckets.size() – (currentPage – 1) limit 到 buckets.size() – currentPage limit 条记录。
// 获取到 response 之后
Aggregations aggregations = response.getAggregations();
Terms carids = aggregations.get(“group_car_bayId”);
List<? extends Terms.Bucket> buckets = carids.getBuckets();
List<carBean> listCarTgs = new ArrayList<>();
carBean carBean ;
// buckets 全部数据，分页就是取固定位置的 limit 条数据
// 默认按照统计之后的数量倒序，如果要正序，则第一页从最后一条开始取
if(buckets.size()>0) {
int i=0;
if(“desc”.equalsIgnoreCase(order)) {// 倒序
for(Terms.Bucket bucket : buckets){
if(i++<(currentPage-1) * limit){
continue;
}
if (i > currentPage * limit) {
break;
}
carBean = new carBean();
carBean.setPassTimes((int)bucket.getDocCount());
carBean.setBayId(bucket.getKeyAsString().split(“_”)[2]);
carBean.setPlateNumber(bucket.getKeyAsString().split(“_”)[0]);
carBean.setPlateType(bucket.getKeyAsString().split(“_”)[1]);
listCarTgs.add(carBean);
}
}else if(“asc”.equalsIgnoreCase(order)) {// 升序
for(i = buckets.size() – 1; i >= 0; i–){
if(i < buckets.size() – currentPage * limit){
break;
}
if(i > buckets.size() – (currentPage – 1) * limit) continue;;
carBean = new carBean();
carBean.setPassTimes((int)buckets.get(i).getDocCount());
carBean.setBayId(buckets.get(i).getKeyAsString().split(“_”)[2]);
carBean.setPlateNumber(buckets.get(i).getKeyAsString().split(“_”)[0]);
carBean.setPlateType(buckets.get(i).getKeyAsString().split(“_”)[1]);
listCarTgs.add(carBean);
}
}
}
单个 group
注意：需要设置 size
TermsAggregationBuilder tb= AggregationBuilders.terms(“group_bayId”).field(“bay_id”).size(Integer.MAX_VALUE);
多个 group
以脚本的形式
TermsAggregationBuilder tb= AggregationBuilders.terms(“group_carId”).script(new Script(“doc[‘plateNumber’].value+’_’+doc[‘plateType’].value”));
tb.subAggregation(AggregationBuilders.topHits(“max_time”).sort(“reportTime”, SortOrder.DESC).size(1));
再比如：三个 group
BoolQueryBuilder filter = QueryBuilders.boolQuery();
if (carList != null && carList.size() >0) {
filter.must(QueryBuilders.termsQuery(“car_plate_number”, carList.stream().map(SimpleCar:: getPlateNumber).collect(Collectors.toList())));
}
if (startTime != null && endTime != null) {
filter.filter(QueryBuilders.rangeQuery(“timestamp”).gt(startTime.getTime()).lt(endTime.getTime()));
} else if (startTime != null) {
filter.filter(QueryBuilders.rangeQuery(“timestamp”).gt(startTime.getTime()));
} else if (endTime != null) {
filter.filter(QueryBuilders.rangeQuery(“timestamp”).lt(endTime.getTime()));
}
FieldSortBuilder sort = SortBuilders.fieldSort(“transit_times”).order(“asc”.equalsIgnoreCase(order)?SortOrder.ASC:SortOrder.DESC);
TermsAggregationBuilder termsAggregationBuilder = AggregationBuilders.terms(“group_car_bayId”)
.script(new Script(“doc[‘car_plate_number’].value+’_’+doc[‘car_plate_type’].value + ‘_’ +doc[‘bay_id’].value”)).size(Integer.MAX_VALUE);
SearchResponse response = search(filter, sort, termsAggregationBuilder, elasticsearchProperties.getTgsIndex(), elasticsearchProperties.getTgsType(),
(currentPage-1) * limit, 0);
Aggregations aggregations = response.getAggregations();
例子 2：
TermsAggregationBuilder tb= AggregationBuilders.terms(“group_bayId”).field(“bay_id”).size(Integer.MAX_VALUE);
tb.order(BucketOrder.count(false));
