记录贴 Elasticsearch的RestClient进行DSL查询

• must：必须匹配每个子查询，类似“与”

• should：选择性匹配子查询，类似“或”

• must_not：必须不匹配，不参与算分，类似“非”

• filter：必须匹配，不参与算分

import cn.hutool.json.JSONUtil;
import com.hmall.item.domain.po.ItemDoc;
import com.hmall.item.service.IItemService;
import lombok.extern.slf4j.Slf4j;
import org.apache.http.HttpHost;
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.QueryBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.io.IOException;

@Slf4j
@SpringBootTest(properties = "spring.profiles.active=local")
public class ElassticSearchTest {

    private RestHighLevelClient client;
    @Autowired
    private IItemService itemService;

    @BeforeEach
    void setUp() {
        this.client = new RestHighLevelClient(RestClient.builder(
                HttpHost.create("http://192.168.48.129:9200")
        ));
    }

    @AfterEach
    void tearDown() throws IOException {
        this.client.close();
    }


    @Test
    void testMatchAll() throws IOException {
        // 1.创建Request
        SearchRequest request = new SearchRequest("items");
        // 2.组织请求参数
        request.source().query(QueryBuilders.matchAllQuery());
        // 3.发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 4.解析响应
        handleResponse(response);
    }

    private void handleResponse(SearchResponse response) {
        SearchHits searchHits = response.getHits();
        // 1.获取总条数
        long total = searchHits.getTotalHits().value;
        System.out.println("共搜索到" + total + "条数据");
        // 2.遍历结果数组
        SearchHit[] hits = searchHits.getHits();
        for (SearchHit hit : hits) {
            // 3.得到_source，也就是原始json文档
            String source = hit.getSourceAsString();
            // 4.反序列化并打印
            ItemDoc item = JSONUtil.toBean(source, ItemDoc.class);
            // 5.1处理高亮
            Map<String, HighlightField> hfs = hit.getHighlightFields();
            // 5.2判断是否有高亮
            if(hfs != null && !hfs.isEmpty()){
                // 5.3获取高亮
                HighlightField hf = hfs.get("name");
                // 5.4获取高亮内容
                String hfName = hf.getFragments()[0].string();
                item.setName(hfName);
            }

            System.out.println(item);
        }
    }

    @Test
    void testMatch() throws IOException {
        // 1.创建Request
        SearchRequest request = new SearchRequest("items");
        // 2.组织请求参数
        request.source().query(QueryBuilders.matchQuery("name", "脱脂牛奶"));
        // 3.发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 4.解析响应
        handleResponse(response);
    }

    @Test
    void testMultiMatch() throws IOException {
        // 1.创建Request
        SearchRequest request = new SearchRequest("items");
        // 2.组织请求参数
        request.source().query(QueryBuilders.multiMatchQuery("脱脂牛奶", "name", "category"));
        // 3.发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 4.解析响应
        handleResponse(response);
    }

    @Test
    void testRange() throws IOException {
        // 1.创建Request
        SearchRequest request = new SearchRequest("items");
        // 2.组织请求参数
        request.source().query(QueryBuilders.rangeQuery("price").gte(10000).lte(30000));
        // 3.发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 4.解析响应
        handleResponse(response);
    }

    @Test
    void testTerm() throws IOException {
        // 1.创建Request
        SearchRequest request = new SearchRequest("items");
        // 2.组织请求参数
        request.source().query(QueryBuilders.termQuery("brand", "华为"));
        // 3.发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 4.解析响应
        handleResponse(response);
    }

    @Test
    void testBool() throws IOException {
    // 1.创建Request
    SearchRequest request = new SearchRequest("items");
    // 2.组织请求参数
    // 2.1.准备bool查询
    BoolQueryBuilder bool = QueryBuilders.boolQuery();
    // 2.2.关键字搜索
    bool.must(QueryBuilders.matchQuery("name", "脱脂牛奶"));
    // 2.3.品牌过滤
    bool.filter(QueryBuilders.termQuery("brand", "德亚"));
    // 2.4.价格过滤
    bool.filter(QueryBuilders.rangeQuery("price").lte(30000));
    request.source().query(bool);
    // 3.发送请求
    SearchResponse response = client.search(request, RequestOptions.DEFAULT);
    // 4.解析响应
    handleResponse(response);
}
    
    @Test
    void testPageAndSort() throws IOException {
        int pageNo = 1, pageSize = 5;

        // 1.创建Request
        SearchRequest request = new SearchRequest("items");
        // 2.组织请求参数
        // 2.1.搜索条件参数
        request.source().query(QueryBuilders.matchQuery("name", "脱脂牛奶"));
        // 2.2.排序参数
        request.source().sort("price", SortOrder.ASC);
        // 2.3.分页参数
        request.source().from((pageNo - 1) * pageSize).size(pageSize);
        // 3.发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 4.解析响应
        handleResponse(response);
    }
    
    @Test
    void testHighlight() throws IOException {
        // 1.创建Request
        SearchRequest request = new SearchRequest("items");
        // 2.组织请求参数
        // 2.1.query条件
        request.source().query(QueryBuilders.matchQuery("name", "脱脂牛奶"));
        // 2.2.高亮条件
        request.source().highlighter(
                SearchSourceBuilder.highlight()
                    .field("name")
                    .preTags("<em>")
                    .postTags("</em>")
        );
        // 3.发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 4.解析响应
        handleResponse(response);
    }

    //聚合
    @Test
    void testAgg() throws IOException {
        // 1.创建Request
        SearchRequest request = new SearchRequest("items");
        // 2.准备请求参数
        BoolQueryBuilder bool = QueryBuilders.boolQuery()
                .filter(QueryBuilders.termQuery("category", "手机"))
                .filter(QueryBuilders.rangeQuery("price").gte(300000));
        request.source().query(bool).size(0);
        // 3.聚合参数
        request.source().aggregation(
                AggregationBuilders.terms("brand_agg").field("brand").size(5)
        );
        // 4.发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 5.解析聚合结果
        Aggregations aggregations = response.getAggregations();
        // 5.1.获取品牌聚合
        Terms brandTerms = aggregations.get("brand_agg");
        // 5.2.获取聚合中的桶
        List<? extends Terms.Bucket> buckets = brandTerms.getBuckets();
        // 5.3.遍历桶内数据
        for (Terms.Bucket bucket : buckets) {
            // 5.4.获取桶内key
            String brand = bucket.getKeyAsString();
            System.out.print("brand = " + brand);
            long count = bucket.getDocCount();
            System.out.println("; count = " + count);
        }
    }

}