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Elasticsearch教程(4) High Level REST Client API 查询 聚合 分组

时间:2024-02-19 01:59:13

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Elasticsearch教程(4) High Level REST Client API 查询 聚合 分组

ES High Level REST Client API 查询 聚合

1 准备数据1.1 插入测试数据2 Maven引入ES3 创建Client4 查询API4.1 根据id查询单条数据4.2 根据多个id查询4.3 根据条件分页查询4.4 count4.5 max5 terms聚合5.1 根据1个字段group by5.2 根据多个字段group by

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1 准备数据

首先启动好的ES6.8服务和Kibana服务

1.1 插入测试数据

假设有个部门组织的场景,部门有上级部门或者下级部门,像一颗树那样

PUT /dept/_doc/1{"code": "dept_1","name": "部门1","level": 1,"path": "1","parentId": "","status":1}PUT /dept/_doc/2{"code": "dept_2","name": "部门2","level": 1,"path": "2","parentId": "","status":0}PUT /dept/_doc/3{"code": "dept_1_1","name": "部门1_1","level": 2,"path": "1,3","parentId": "1","status":0}PUT /dept/_doc/4{"code": "dept_1_2","name": "部门1_2","level": 2,"path": "1,4","parentId": "1","status":0}PUT /dept/_doc/5{"code": "dept_1_1_1","name": "部门1_1_1","level": 3,"path": "1,3,5","parentId": "3","status":1}PUT /dept/_doc/6{"code": "dept_1_1_2","name": "部门1_1_2","level": 3,"path": "1,3,6","parentId": "3","status":null}

数据结果如下:

2 Maven引入ES

新建一个空的Maven结构项目,在pom.xml里添加如下

<dependency><groupId>org.elasticsearch.client</groupId><artifactId>elasticsearch-rest-high-level-client</artifactId><version>6.8.4</version></dependency>

3 创建Client

public class EsRestUtils {private static RestHighLevelClient client;private static final String type = "_doc";public static RestHighLevelClient getClient() {if (client == null) {client = new RestHighLevelClient(RestClient.builder(new HttpHost("192.168.8.201", 9200, "http")));}return client;}}

4 查询API

4.1 根据id查询单条数据

用SQL描述就是

select * from dept where id = '1'

protected static Map<String, Object> getById(String index, String id) throws IOException {getClient();GetRequest getRequest = new GetRequest(index, type, id);GetResponse getResponse = client.get(getRequest, RequestOptions.DEFAULT);if (getResponse.isExists()){return getResponse.getSourceAsMap();}return null;}

4.2 根据多个id查询

用SQL描述就是

select * from dept where id in ("1", "2", "3")

protected static List<Map<String, Object>> getByIds(String index, List<String> ids) throws IOException {getClient();List<Map<String, Object>> results = new ArrayList<>();MultiGetRequest request = new MultiGetRequest();ids.stream().forEach(id -> {request.add(new MultiGetRequest.Item(index, type, id));});MultiGetResponse response = client.mget(request, RequestOptions.DEFAULT);GetResponse getResponse;for (int i = 0; i < response.getResponses().length; i++) {getResponse = response.getResponses()[i].getResponse();if (getResponse.isExists()) {results.add(getResponse.getSourceAsMap());}}return results;}

4.3 根据条件分页查询

用SQL描述就是

select * from dept where id in ("1", "2", "3") limt 2,10

protected static List<Map<String, Object>> getByWhere(String index, QueryBuilder queryBuilder, int pageNo, int pageSize) throws IOException {getClient();List<Map<String, Object>> results = new ArrayList<>();SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();searchSourceBuilder.query(queryBuilder);searchSourceBuilder.from(pageNo);searchSourceBuilder.size(pageSize);SearchRequest searchRequest = new SearchRequest(index).types(type);searchRequest.source(searchSourceBuilder);SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);SearchHits hits = searchResponse.getHits();SearchHit[] searchHits = hits.getHits();for (SearchHit hit : searchHits) {results.add(hit.getSourceAsMap());}return results;}

4.4 count

用SQL描述就是

select count(1) from dept where name like '部门%'

public static long count(QueryBuilder queryBuilder, String... indexs) throws IOException {getClient();SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();searchSourceBuilder.query(queryBuilder);CountRequest countRequest = new CountRequest(indexs);countRequest.source(searchSourceBuilder);CountResponse countResponse = client.count(countRequest, RequestOptions.DEFAULT);long count = countResponse.getCount();return count;}

4.5 max

用SQL描述就是

select max(level) from dept where name like '部门%'

public static Double getMax(QueryBuilder queryBuilder, String field, String... indexs) throws IOException {getClient();SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();searchSourceBuilder.query(queryBuilder);searchSourceBuilder.size(0);AggregationBuilder aggregationBuilder = AggregationBuilders.max("agg").field(field);searchSourceBuilder.aggregation(aggregationBuilder);SearchRequest searchRequest = new SearchRequest(indexs).types(type);searchRequest.source(searchSourceBuilder);SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);Max agg = searchResponse.getAggregations().get("agg");return agg.getValue();}

5 terms聚合

5.1 根据1个字段group by

用SQL描述就是

select level, count(id) from dept where name like '部门%' group by level

public static Map<String, Long> getTermsAgg(QueryBuilder queryBuilder, String field, String... Map<String, Long> groupMap = new HashMap<>();getClient();SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();searchSourceBuilder.query(queryBuilder);searchSourceBuilder.size(0);AggregationBuilder aggregationBuilder = AggregationBuilders.terms("agg").field(field);searchSourceBuilder.aggregation(aggregationBuilder);SearchRequest searchRequest = new SearchRequest(indexs).types(type);searchRequest.source(searchSourceBuilder);SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);Terms terms = searchResponse.getAggregations().get("agg");for (Terms.Bucket entry : terms.getBuckets()) {groupMap.put(entry.getKey().toString(), entry.getDocCount());}return groupMap;}

写代码测试

protected static void testGetTermsAgg(String index) {QueryBuilder queryBuilder = QueryBuilders.wildcardQuery("name.keyword", "部门*");try {Map<String, Long> groupMap = EsRestUtils.getTermsAgg(queryBuilder, "level", index);groupMap.forEach((key, value) -> System.out.println(key + " -> " + value.toString()));} catch (IOException e) {e.printStackTrace();}}

运行结果如下,左边是level,右边是个数

1 -> 22 -> 23 -> 2

5.2 根据多个字段group by

用SQL描述就是

select level, status, count(id) from dept where name like '部门%' group by level, status

public static Map<String, Map<String, Long>> getTermsAggTwoLevel(QueryBuilder queryBuilder, String field1, String field2, String... indexs) throws IOException {Map<String, Map<String, Long>> groupMap = new HashMap<>();getClient();SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();searchSourceBuilder.query(queryBuilder);searchSourceBuilder.size(0);AggregationBuilder agg1 = AggregationBuilders.terms("agg1").field(field1);AggregationBuilder agg2 = AggregationBuilders.terms("agg2").field(field2);agg1.subAggregation(agg2);searchSourceBuilder.aggregation(agg1);SearchRequest searchRequest = new SearchRequest(indexs).types(type);searchRequest.source(searchSourceBuilder);SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);Terms terms1 = searchResponse.getAggregations().get("agg1");Terms terms2;for (Terms.Bucket bucket1 : terms1.getBuckets()) {terms2 = bucket1.getAggregations().get("agg2");Map<String, Long> map2 = new HashMap<>();for (Terms.Bucket bucket2 : terms2.getBuckets()) {map2.put(bucket2.getKey().toString(), bucket2.getDocCount());}groupMap.put(bucket1.getKey().toString(), map2);}return groupMap;}

写代码测试

protected static void testGetTermsAgg2(String index) {QueryBuilder queryBuilder = QueryBuilders.wildcardQuery("name.keyword", "部门*");try {Map<String, Map<String, Long>> groupMap = EsRestUtils.getTermsAggTwoLevel(queryBuilder, "level", "status", index);groupMap.forEach((key, value) -> System.out.println(key + " -> " + value.toString()));} catch (IOException e) {e.printStackTrace();}}

对于id=6的那条数据,status=null,就不会统计到,如果没有status也不会统计到。

1 -> {0=1, 1=1}#leve=1的数据中,status=1的1条,status=0的1条2 -> {0=2}#leve=2的数据中,status=0的2条3 -> {1=1}#leve=3的数据中,status=1的1条

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