ElasticSearch的DSL查询

准备工作

创建测试方法，初始化测试结构。

import org.apache.http.HttpHost;
import org.apache.lucene.search.TotalHits;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
import org.elasticsearch.search.sort.SortOrder;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;import java.io.IOException;
import java.util.Map;public class DemoTest {private RestHighLevelClient client;/*** * 因为下面会重复使用输出语句所以就单独抽出来封装了** @param response 查询结果响应体*/public static void handelResponse(SearchResponse response) {// 查询的总数TotalHits total = response.getHits().getTotalHits();System.out.println("total===>" + total);SearchHits searchHits = response.getHits();// 输出查询结果searchHits.forEach(hit -> {// 查询时JSON数据，可以使用实体将其转换。String json = hit.getSourceAsString();System.out.println(json);// 高亮返回体Map<String, HighlightField> map = hit.getHighlightFields();if (map != null) {System.out.println("-----------------高亮显示---------------");HighlightField highlightField = map.get("name");System.out.println("name===>" + highlightField.getName());System.out.println("fragments===>" + highlightField.getFragments()[0]);}});}@BeforeEachvoid setup() {this.client = new RestHighLevelClient(RestClient.builder(HttpHost.create("http://192.168.3.98:9200")));}@AfterEachvoid teardown() throws IOException {this.client.close();}
}

DSL查询

普通查询全部

new SearchRequest("hotel")查询索引库名称。

@Test
void testMatchAll() throws IOException {// 指定查询的索引库SearchRequest request = new SearchRequest("hotel");// 查询全部内容request.source().query(QueryBuilders.matchAllQuery());// 得到查询返回体，传入返回体到封装的返回体输出SearchResponse response = client.search(request, RequestOptions.DEFAULT);handelResponse(response);
}

对应控制台。

# 查询所有
GET /_search
{"query": {"match_all": {}}
}

match查询-单字段查询

// match查询-单字段查询
@Test
void testMatch() throws IOException {// 指定查询的索引库SearchRequest request = new SearchRequest("hotel");// 查询内容request.source().query(QueryBuilders.matchQuery("all", "如家"));// 得到查询返回体，传入返回体到封装的返回体输出SearchResponse response = client.search(request, RequestOptions.DEFAULT);handelResponse(response);
}

对应控制台。

# match，根据单字段查询，推荐使用
GET /hotel/_search
{"query": {"match": {"all": "外滩如家"}}
}

match查询-多字段查询

@Test
void testMultiMatchQuery() throws IOException {// 指定查询的索引库SearchRequest request = new SearchRequest("hotel");// 查询内容request.source().query(QueryBuilders.multiMatchQuery("如家", "name", "business"));// 得到查询返回体，传入返回体到封装的返回体输出SearchResponse response = client.search(request, RequestOptions.DEFAULT);handelResponse(response);
}

对应控制台。

# multi_match 多字段查询，不推荐，性能低
GET /hotel/_search
{"query": {"multi_match": {"query": "外滩如家","fields": ["name","brand","business"]}}
}

精确查询

@Test
void termQuery() throws IOException {// 指定查询的索引库SearchRequest request = new SearchRequest("hotel");// 查询内容-精确查找request.source().query(QueryBuilders.termQuery("city", "深圳"));// 得到查询返回体，传入返回体到封装的返回体输出SearchResponse response = client.search(request, RequestOptions.DEFAULT);handelResponse(response);
}

对应控制台。

# 精确查找-term，不会分词
GET /hotel/_search
{"query": {"term": {"city": {"value": "上海"}}}
}

范围查找

@Test
void testRange() throws IOException {// 指定查询的索引库SearchRequest request = new SearchRequest("hotel");// 查询内容request.source().query(QueryBuilders.rangeQuery("price").gte(100).lt(150));// 得到查询返回体，传入返回体到封装的返回体输出SearchResponse response = client.search(request, RequestOptions.DEFAULT);handelResponse(response);
}

对应控制台。

# range 范围查询
GET /hotel/_search
{"query": {"range": {"price": {"gte": 100,"lte": 300}}}
}

布尔查询

@Test
void testBoolean() throws IOException {// 指定查询的索引库SearchRequest request = new SearchRequest("hotel");// 查询内容BoolQueryBuilder query = QueryBuilders.boolQuery();query.must(QueryBuilders.termQuery("city", "杭州"));query.filter(QueryBuilders.rangeQuery("price").lt(250));// 得到查询返回体，传入返回体到封装的返回体输出SearchResponse response = client.search(request, RequestOptions.DEFAULT);handelResponse(response);
}

对应控制台。

# 不等于gt，lt不等于
GET /hotel/_search
{"query": {"range": {"FIELD": {"gt": 10,"lt": 20}}}
}

排序、分页

@Test
void testFrom() throws IOException {// 页码，每页大小int page = 1, size = 5;// 指定查询的索引库SearchRequest request = new SearchRequest("hotel");// 查询内容request.source().query(QueryBuilders.matchAllQuery());request.source().from((page - 1) * size).size(5);request.source().sort("price", SortOrder.ASC);// 得到查询返回体，传入返回体到封装的返回体输出SearchResponse response = client.search(request, RequestOptions.DEFAULT);handelResponse(response);
}

高亮

@Test
void testHighLighter() throws IOException {// 指定查询的索引库SearchRequest request = new SearchRequest("hotel");// 查询内容request.source().query(QueryBuilders.matchQuery("all", "如家"));request.source().highlighter(new HighlightBuilder().field("name").requireFieldMatch(false));// 得到查询返回体，传入返回体到封装的返回体输出SearchResponse response = client.search(request, RequestOptions.DEFAULT);handelResponse(response);
}

对应控制台。

# 搜索结果高亮显示，默认字段必须与高亮字段一致，默认是em标签
GET /hotel/_search
{"query": {"match": {"all": "如家"}},"highlight": {"fields": {"name": {"require_field_match": "false","pre_tags": "<i>","post_tags": "</i>"}}}, "from": 0,"size": 20
}