elasticsearch7.17.3实现按terms传入内容排序，类似mysql中order by filed()的排序方式

现有一个需求，需要在elasticsearch中实现用terms筛选内容，并且按terms传入的内容顺序排列
类型于mysql中order by filed()的排序方式，具体实现如下

一、需求

筛选 fileId 为"3",“2”,“1”,“4”,“5"的记录，并且按照"3”,“2”,“1”,“4”,"5"方式排序

二、整体思路

用terms实现数据的筛选，使用传入集合的索引当作排序的依据

三、es查询语句

terms中是筛选数据内容
sort中是自定义排序规则，将集合索引当作排序的依据

注意：sort 中的 order 内容需要为字符串集合，如果为数字集合，则此排序规则会失效

POST test/_search
{"query": {"bool": {"must": [{"terms": {"fileId": ["3","2","1","4","5"]}}]}},"sort": [{"_script": {"type": "number","order": "asc","script": {"source": "params.order.indexOf(doc['fileId'].value.toString())","params": {"order": ["3","2","1","4","5"]}}}}]
}

四、java生成es连接

	//生成es连接private ElasticsearchClient getEsClient() {try {//调用es有同步和异步之分，下列方法是同步阻塞调用// Create the low-level clientRestClient restClient = RestClient.builder(new HttpHost("127.0.0.1", 9200)).build();// Create the transport with a Jackson mapperElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());// And create the API clientElasticsearchClient client = new ElasticsearchClient(transport);return client;} catch (Exception e) {e.printStackTrace();log.error("生成esClient失败" + e);}return null;}

五、java调用es

下面方法是对java调用es实现第三步中的查询方式

注意：sort 中的 order 内容仍然需要传入字符串格式集合，否则排序都为 -1，无法实现想要的排序效果

public void test() throws Exception {//基本数据准备List<Long> fileIdList = new ArrayList<>();fileIdList.add(3L);fileIdList.add(2L);fileIdList.add(1L);fileIdList.add(4L);fileIdList.add(5L);//设置筛选内容List<String> fileIdStrList = new ArrayList<>();List<FieldValue> fileValueList = fileIdList.stream().map(m -> {FieldValue.Builder ff = new FieldValue.Builder();ff.longValue(m);fileIdStrList.add(m.toString());return ff.build();}).collect(Collectors.toList());BoolQuery.Builder queryBuilder = new BoolQuery.Builder();queryBuilder.must(_1 -> _1.terms(_2 -> _2.field("fileId").terms(_3 -> _3.value(fileValueList))));ElasticsearchClient client = getEsClient();//设置排序规则SortOptions.Builder sortOptions2 = new SortOptions.Builder();sortOptions2.script(_1 -> _1.type(ScriptSortType.Number).order(SortOrder.Asc).script(_2 -> _2.inline(_3 -> _3.source("params.order.indexOf(doc['fileId'].value.toString())").params("order", JsonData.of(fileIdStrList)))));SearchResponse<Map> search = client.search(_1 -> _1.index("test")//es默认返回10000条数据，加上此条配置才能返回全部条数.trackTotalHits(_2 -> _2.enabled(true))//查询参数.query(queryBuilder.build()._toQuery()).sort(sortOptions2.build())
//                        .from(pageBegin)
//                        .size(pageSize).source(_2 -> _2.filter(_3 -> _3.includes("fileId"))), Map.class);Long totalNum = search.hits().total().value();  //查询总条数List<Integer> resultFileIdList = search.hits().hits().stream().map(m -> (Integer) m.source().get("fileId")).collect(Collectors.toList());System.out.println(Arrays.asList(resultFileIdList));}