Acesso RestClient elasticsearch

1. Introduzir dependências

1) Introduza a dependência RestHighLevelClient de es:

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

2) Como a versão ES padrão do SpringBoot é 7.6.2, precisamos substituir a versão ES padrão:

<properties>
    <java.version>1.8</java.version>
    <elasticsearch.version>7.12.1</elasticsearch.version>
</properties>

3) Inicialize RestHighLevelClient:

O código de inicialização é o seguinte:

RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(
        HttpHost.create("http://192.168.150.101:9200")
));

2. Crie uma biblioteca de índice e exclua uma biblioteca de índice

Armazena a instrução da biblioteca de índices recém-adicionada

package cn.itcast.hotel;

public class HotelConstants {
    public static final String MAPPING_TEMPLATE = "{\n" +
            "  \"mappings\": {\n" +
            "    \"properties\": {\n" +
            "      \"id\": {\n" +
            "        \"type\": \"keyword\"\n" +
            "      },\n" +
            "      \"name\":{\n" +
            "        \"type\": \"text\",\n" +
            "        \"analyzer\": \"ik_max_word\",\n" +
            "        \"copy_to\": \"all\"\n" +
            "      },\n" +
            "      \"address\":{\n" +
            "        \"type\": \"keyword\",\n" +
            "        \"index\": false\n" +
            "      },\n" +
            "      \"price\":{\n" +
            "        \"type\": \"integer\"\n" +
            "      },\n" +
            "      \"score\":{\n" +
            "        \"type\": \"integer\"\n" +
            "      },\n" +
            "      \"brand\":{\n" +
            "        \"type\": \"keyword\",\n" +
            "        \"copy_to\": \"all\"\n" +
            "      },\n" +
            "      \"city\":{\n" +
            "        \"type\": \"keyword\",\n" +
            "        \"copy_to\": \"all\"\n" +
            "      },\n" +
            "      \"starName\":{\n" +
            "        \"type\": \"keyword\"\n" +
            "      },\n" +
            "      \"business\":{\n" +
            "        \"type\": \"keyword\"\n" +
            "      },\n" +
            "      \"location\":{\n" +
            "        \"type\": \"geo_point\"\n" +
            "      },\n" +
            "      \"pic\":{\n" +
            "        \"type\": \"keyword\",\n" +
            "        \"index\": false\n" +
            "      },\n" +
            "      \"all\":{\n" +
            "        \"type\": \"text\",\n" +
            "        \"analyzer\": \"ik_max_word\"\n" +
            "      }\n" +
            "    }\n" +
            "  }\n" +
            "}";
}

Adicionar e excluir operações de biblioteca de índice 

import org.apache.http.HttpHost;
import org.apache.http.client.methods.HttpPost;
import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.indices.CreateIndexRequest;
import org.elasticsearch.common.xcontent.XContentType;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;

import java.io.IOException;

@SpringBootTest
class HotelSuoYinTest {
    private RestHighLevelClient client;

    @BeforeEach
    void setup() {
        this.client =
                new RestHighLevelClient(
                        RestClient.builder(
                                HttpHost.create("http://101.43.94.150:9200")
                        ));
    }

    @AfterEach
    void shutdown() throws IOException {
        this.client.close();
    }
//    indices()  有这个，就是索引库的操作
    @Test
    void test() throws IOException {
//        创建request对象
        CreateIndexRequest request = new CreateIndexRequest("hotel");
//        准备请求的参数 dsl语句
        request.source(HotelConstants.MAPPING_TEMPLATE, XContentType.JSON);
//        发送请求
        client.indices().create(request, RequestOptions.DEFAULT);
    }

    @Test
    void deltest() throws IOException {
//        创建request对象
        DeleteIndexRequest request = new DeleteIndexRequest("hotel");
//        发送请求
        client.indices().delete(request, RequestOptions.DEFAULT);
    }
}

Determinar se a biblioteca de índices existe 

@Test
void testExistsHotelIndex() throws IOException {
    // 1.创建Request对象
    GetIndexRequest request = new GetIndexRequest("hotel");
    // 2.发送请求
    boolean exists = client.indices().exists(request, RequestOptions.DEFAULT);
    // 3.输出
    System.err.println(exists ? "索引库已经存在！" : "索引库不存在！");
}

As etapas básicas da operação da biblioteca de índices:

• Inicializar RestHighLevelClient

• Criar xxxIndexRequest. XXX é criar, obter, excluir

• Prepare DSL (necessário ao criar, outros não são parâmetros)

• enviar pedido. Chame o método RestHighLevelClient#indices().xxx(), onde xxx é criar, existe, excluir

3. Excluir documentos, modificar documentos, adicionar documentos, adicionar documentos em lotes

Porque as informações de longitude e latitude das informações do hotel consultadas pelo mysql são separadas, mas as coordenadas geográficas do elasticsearch precisam ser do tipo String, separadas por vírgulas no meio, portanto, precisam ser convertidas para hotelDoc

//文档，相当于mysql中的行
//#查询一条文档（记录）的 dsl语句
//        GET /heima/_doc/1
@SpringBootTest
public class DocumentTest {
    private RestHighLevelClient client;
    @Autowired
    HotelService hotelService;

    //    插入新数据
    @Test
    public void testadd() throws IOException {
        Hotel hotel = hotelService.getById(61083L);
        HotelDoc hotelDoc = new HotelDoc(hotel);
//        创建request，并指明要处理的索引是hotel,记录号是 hotelDoc.getId()
        IndexRequest request = new IndexRequest("hotel").id(hotelDoc.getId().toString());
        request.source(JSON.toJSONString(hotelDoc), XContentType.JSON);
        client.index(request, RequestOptions.DEFAULT);
    }

    //    查询某条数据
    @Test
    public void testquery() throws IOException {
        GetRequest request = new GetRequest("hotel", "61083");
        GetResponse response = client.get(request, RequestOptions.DEFAULT);
        String json = response.getSourceAsString();
        HotelDoc hotelDoc = JSON.parseObject(json, HotelDoc.class);
        System.out.println(hotelDoc);
    }

    //更新某条数据
    @Test
    public void testupdate() throws IOException {
        Hotel hotel = hotelService.getById(61083L);
        HotelDoc hotelDoc = new HotelDoc(hotel);
        UpdateRequest request = new UpdateRequest("hotel", "61083");
        request.doc("price", "952");
        request.doc("address", "北京饭店");
        client.update(request, RequestOptions.DEFAULT);
    }

    //   删除某条数据
    @Test
    void testDeleteDocument() throws IOException {
        // 1.准备Request
        DeleteRequest request = new DeleteRequest("hotel", "61083");
        // 2.发送请求
        client.delete(request, RequestOptions.DEFAULT);
    }

    @Test
    void testpiliangadd() throws IOException {
        List<Hotel> hotels = hotelService.list();
        BulkRequest request = new BulkRequest();
        for (Hotel hotel : hotels) {
            HotelDoc hotelDoc = new HotelDoc(hotel);
            request.add(new IndexRequest("hotel")
                    .id(hotelDoc.getId() + "")
                    .source(JSON.toJSONString(hotelDoc)
                            , XContentType.JSON));
        }
        client.bulk(request, RequestOptions.DEFAULT);
    }

    @BeforeEach
    void setup() {
        this.client =
                new RestHighLevelClient(
                        RestClient.builder(
                                HttpHost.create("http://101.43.94.150:9200")
                        ));
    }

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

4. Consultar documentos

package cn.itcast.hotel;

import cn.itcast.hotel.pojo.HotelDoc;
import com.alibaba.fastjson.JSON;
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.BoolQueryBuilder;
import org.elasticsearch.index.query.QueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.SearchHit;
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 org.springframework.boot.test.context.SpringBootTest;

import java.io.IOException;
import java.util.Map;

@SpringBootTest
public class QueryTest {
    private RestHighLevelClient client;

    //查询全部文档
    @Test
    void testmatchall() throws IOException {
//       1. 准备request
        SearchRequest request = new SearchRequest("hotel");
//       2. 准备dsl
        request.source().query(QueryBuilders.matchAllQuery());
//        3.发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        handleResponse(response);
    }

    //全文检索查询
    @Test
    void testquerycheck() throws IOException {
//       1. 准备request
        SearchRequest request = new SearchRequest("hotel");

//       2. 准备dsl
        request.source().query(QueryBuilders.matchQuery("all", "如家"));
//        3.发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        handleResponse(response);
    }

    //boolean复合查询
    @Test
    void testBool() throws IOException {
        // 1.准备Request
        SearchRequest request = new SearchRequest("hotel");
        // 2.准备DSL
        // 2.1.准备BooleanQuery
        BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
        // 2.2.添加term
        boolQuery.must(QueryBuilders.termQuery("city", "上海"));
        // 2.3.添加range
        boolQuery.filter(QueryBuilders.rangeQuery("price").lte(250));
//        关联查询条件
        request.source().query(boolQuery);
        // 3.发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 4.解析响应
        handleResponse(response);
    }

    //查询后排序和按页查询  el的分页查询是查询所有结果之后再分页。
    @Test
    void testpageandsort() throws IOException {
//        页码，每页大小
        int pagenum = 1, pagesize = 5;
        // 1.准备Request
        SearchRequest request = new SearchRequest("hotel");
        request.source().query(QueryBuilders.matchAllQuery());
        request.source().sort("price", SortOrder.ASC);
//       前端传过来的是页码和每页大小 ，算一下从第多少条后开始分页
        request.source().from((pagenum - 1) * pagesize);
//        页大小
        request.source().size(pagesize);
        // 3.发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 4.解析响应
        handleResponse(response);
    }

    //查询后高亮显示
    @Test
    void testhightlight() throws IOException {
        // 1.准备Request
        SearchRequest request = new SearchRequest("hotel");
        request.source().query(QueryBuilders.matchQuery("brand", "如家"));
//        requireFieldMatch(false) 搜索条件brand和高亮的属性name设为不一致
        request.source().highlighter(new HighlightBuilder().field("name").requireFieldMatch(false));
        // 3.发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        handleHeightLightResponse(response);
    }
    
//    高亮查询
    private void handleHeightLightResponse(SearchResponse response) {
        // 4.解析响应
        SearchHits searchHits = response.getHits();
        // 4.1.获取总条数
        long total = searchHits.getTotalHits().value;
        System.out.println("共搜索到" + total + "条数据");
        // 4.2.文档数组
        SearchHit[] hits = searchHits.getHits();
        // 4.3.遍历
        for (SearchHit hit : hits) {
            // 获取文档source
            String json = hit.getSourceAsString();
            // 反序列化
            HotelDoc hotelDoc = JSON.parseObject(json, HotelDoc.class);
//             获取高亮
            Map<String, HighlightField> highlightFields = hit.getHighlightFields();
            HighlightField highlightField = highlightFields.get("name");
            String name = highlightField.getFragments()[0].toString();
            hotelDoc.setName(name);
            System.out.println(hotelDoc);
        }
    }
// 解析响应函数
    private void handleResponse(SearchResponse response) {
        // 4.解析响应
        SearchHits searchHits = response.getHits();
        // 4.1.获取总条数
        long total = searchHits.getTotalHits().value;
        System.out.println("共搜索到" + total + "条数据");
        // 4.2.文档数组
        SearchHit[] hits = searchHits.getHits();
        // 4.3.遍历
        for (SearchHit hit : hits) {
            // 获取文档source
            String json = hit.getSourceAsString();
            // 反序列化
            HotelDoc hotelDoc = JSON.parseObject(json, HotelDoc.class);
//            System.out.println("hotelDoc = " + hotelDoc);
        }
    }

    @BeforeEach
    void setup() {
        this.client =
                new RestHighLevelClient(
                        RestClient.builder(
                                HttpHost.create("http://101.43.94.150:9200")
                        ));
    }

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