ElasticSearch7.8快速入门

1.基本概念

1.数据格式

2.倒排索引

2.HTTP使用

1.创建索引（相当于创建数据库）

2.索引-查询 & 删除

1.查询索引

2.查询所有索引

3.删除索引

3.创建文档

1.创建文档（不指定id）

2.创建文档（指定id）

4.文档-查询 & 查询全部

1.根据id查询文档

2.查询索引下的所有文档

5.文档-修改 & 删除

1.全量修改

2.局部修改

3.删除文档

6.ES高级查询

1.条件查询

2.条件查询（请求体方式）

3.分页查询（查询第二页的数据）

4.分页查询只显示指定字段数据

5.分页查询对查询出的结果进行排序

6.多条件查询

1.must（相当于and）

2.should（相当于or）

3.范围查询价格大于3999

7.完全匹配（match是使用的分词加倒排索引相当于模糊查询）

8.高亮

9.分组统计

10.求所有价格的平均值

11.映射关系

1.创建索引 user

2.给索引创建映射关系

3.Java API

1.环境搭建

1.创建项目

2.引入依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.sunxiansheng</groupId><artifactId>es-demo</artifactId><version>1.0-SNAPSHOT</version><properties><maven.compiler.source>8</maven.compiler.source><maven.compiler.target>8</maven.compiler.target><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding></properties><dependencies><dependency><groupId>org.elasticsearch</groupId><artifactId>elasticsearch</artifactId><version>7.8.0</version></dependency><!-- es客户端 --><dependency><groupId>org.elasticsearch.client</groupId><artifactId>elasticsearch-rest-high-level-client</artifactId><version>7.8.0</version></dependency><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-api</artifactId><version>2.8.2</version></dependency><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-core</artifactId><version>2.8.2</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId><version>2.9.9</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.34</version></dependency></dependencies>
</project>

3.测试连接

package com.sunxiansheng.es;import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;/*** Description: ES测试** @Author sun* @Create 2024/12/5 19:22* @Version 1.0*/
public class ESTest {public static void main(String[] args) {// 连接esRestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("152.136.40.209", 9200, "http")));// 关闭try {client.close();} catch (Exception e) {e.printStackTrace();}}
}

4.封装ES连接工具类

package com.sunxiansheng.es;import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;import java.util.function.Consumer;/*** Description: ES的连接操作工具类** @Author sun* @Create 2024/12/5 19:37* @Version 1.0*/
public class EsUtil {public static void es(Consumer<RestHighLevelClient> consumer) {// 连接esRestHighLevelClient client = new RestHighLevelClient(RestClient.builder(new HttpHost("152.136.40.209", 9200, "http")));consumer.accept(client);// 关闭try {client.close();} catch (Exception e) {e.printStackTrace();}}
}

2.索引操作

1.创建索引

1.代码

package com.sunxiansheng.es;import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.indices.CreateIndexRequest;
import org.elasticsearch.client.indices.CreateIndexResponse;import java.io.IOException;/*** Description: 索引操作** @Author sun* @Create 2024/12/5 19:37* @Version 1.0*/
public class Index {public static void main(String[] args) {EsUtil.es((esClient) -> {// 创建索引CreateIndexRequest request = new CreateIndexRequest("user");// 获取响应结果try {CreateIndexResponse createIndexResponse = esClient.indices().create(request, RequestOptions.DEFAULT);if (createIndexResponse.isAcknowledged()) {System.out.println("创建索引成功");} else {System.out.println("创建索引失败");}} catch (IOException e) {throw new RuntimeException(e);}});}
}

2.结果

2.查询索引

    /*** 查询索引*/@Testpublic void getIndex() {EsUtil.es((esClient) -> {// 查询索引GetIndexRequest request = new GetIndexRequest("user");try {GetIndexResponse getIndexResponse = esClient.indices().get(request, RequestOptions.DEFAULT);System.out.println(getIndexResponse.getAliases());System.out.println(getIndexResponse.getMappings());System.out.println(getIndexResponse.getSettings());} catch (IOException e) {throw new RuntimeException(e);}});}

3.删除索引

    /*** 删除索引*/@Testpublic void deleteIndex() {EsUtil.es((esClient) -> {// 删除索引try {AcknowledgedResponse acknowledgedResponse = esClient.indices().delete(new DeleteIndexRequest("user"), RequestOptions.DEFAULT);if (acknowledgedResponse.isAcknowledged()) {System.out.println("删除索引成功");} else {System.out.println("删除索引失败");}} catch (IOException e) {throw new RuntimeException(e);}});}

3.文档操作

1.添加文档

1.实体类

package com.sunxiansheng.entity;import lombok.Data;/*** Description: 用户实体类** @Author sun* @Create 2024/12/5 20:01* @Version 1.0*/
@Data
public class User {private String name;private Integer age;private String sex;
}

2.代码

    /*** 添加文档*/@Testpublic void addDoc() {EsUtil.es((esClient) -> {// 添加文档// 构建一个索引请求IndexRequest request = new IndexRequest("user");// 设置文档idrequest.id("1001");// 设置文档内容User user = new User();user.setName("张三");user.setAge(20);user.setSex("男");// 将数据转换为json格式ObjectMapper objectMapper = new ObjectMapper();try {String userJson = objectMapper.writeValueAsString(user);// 设置文档内容request.source(userJson, XContentType.JSON);} catch (JsonProcessingException e) {throw new RuntimeException(e);}// 执行操作try {IndexResponse response = esClient.index(request, RequestOptions.DEFAULT);System.out.println("response.getResult() = " + response.getResult());} catch (IOException e) {throw new RuntimeException(e);}});}

2.修改文档

1.代码

    /*** 修改文档*/@Testpublic void updateDoc() {EsUtil.es((esClient) -> {// 添加文档// 构建一个索引请求UpdateRequest request = new UpdateRequest();request.index("user").id("1001");// 将性别修改为女request.doc(XContentType.JSON, "sex", "女");// 执行操作UpdateResponse update = null;try {update = esClient.update(request, RequestOptions.DEFAULT);} catch (IOException e) {throw new RuntimeException(e);}System.out.println("update.getResult() = " + update.getResult());});}

2.结果

3.查询文档

    /*** 查询文档*/@Testpublic void searchDoc() {EsUtil.es((esClient) -> {// 查询指定索引下指定id的文档GetRequest user = new GetRequest("user", "1001");try {GetResponse response = esClient.get(user, RequestOptions.DEFAULT);System.out.println("response.getSourceAsString() = " + response.getSourceAsString());} catch (IOException e) {throw new RuntimeException(e);}});}

4.删除文档

@Test
public void deleteDoc() {EsUtil.es((esClient) -> {// 删除文档try {DeleteRequest user = new DeleteRequest("user", "1001");DeleteResponse response = esClient.delete(user, RequestOptions.DEFAULT);System.out.println("response.toString() = " + response.toString());} catch (IOException e) {throw new RuntimeException(e);}});
}

5.批量新增

    /*** 批量新增*/@Testpublic void batchAdditions() {EsUtil.es((esClient) -> {BulkRequest bulkRequest = new BulkRequest();bulkRequest.add(new IndexRequest("user").id("1002").source(XContentType.JSON, "name", "李四"));bulkRequest.add(new IndexRequest("user").id("1003").source(XContentType.JSON, "name", "王五"));try {BulkResponse response = esClient.bulk(bulkRequest, RequestOptions.DEFAULT);System.out.println("response.getTook() = " + response.getTook());} catch (IOException e) {throw new RuntimeException(e);}});}

6.批量删除

    @Testpublic void batchDeletion() {EsUtil.es((esClient) -> {BulkRequest bulkRequest = new BulkRequest();bulkRequest.add(new DeleteRequest("user").id("1002"));bulkRequest.add(new DeleteRequest("user").id("1003"));try {BulkResponse response = esClient.bulk(bulkRequest, RequestOptions.DEFAULT);System.out.println("response.getTook() = " + response.getTook());} catch (IOException e) {throw new RuntimeException(e);}});}

4.高级查询

1.全量查询

    /*** 全量查询*/@Testpublic void fullQuery() {EsUtil.es((esClient) -> {SearchRequest request = new SearchRequest("user");request.source(new SearchSourceBuilder().query(QueryBuilders.matchAllQuery()));try {SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);SearchHits hits = response.getHits();System.out.println("hits.getTotalHits() = " + hits.getTotalHits());hits.forEach(hit -> {System.out.println("hit.getSourceAsString() = " + hit.getSourceAsString());});} catch (IOException e) {throw new RuntimeException(e);}});}

2.分页查询

    /*** 分页查询*/@Testpublic void pagingSearch() {EsUtil.es((esClient) -> {SearchRequest request = new SearchRequest("user");// 条件查询+分页查询SearchSourceBuilder builder = new SearchSourceBuilder().query(QueryBuilders.matchQuery("name", "李四"));builder.from(0);builder.size(1);request.source(builder);try {SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);SearchHits hits = response.getHits();System.out.println("hits.getTotalHits() = " + hits.getTotalHits());hits.forEach(hit -> {System.out.println("hit.getSourceAsString() = " + hit.getSourceAsString());});} catch (IOException e) {throw new RuntimeException(e);}});}

3.排序查询

    /*** 排序查询*/@Testpublic void sortingQueries() {EsUtil.es((esClient) -> {SearchRequest request = new SearchRequest("user");// 查询所有，根据age升序排序SearchSourceBuilder builder = new SearchSourceBuilder().query(QueryBuilders.matchAllQuery());builder.sort("age", SortOrder.ASC);request.source(builder);try {SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);SearchHits hits = response.getHits();System.out.println("hits.getTotalHits() = " + hits.getTotalHits());hits.forEach(hit -> {System.out.println("hit.getSourceAsString() = " + hit.getSourceAsString());});} catch (IOException e) {throw new RuntimeException(e);}});}

4.过滤字段

    /*** 过滤字段*/@Testpublic void filterFields() {EsUtil.es((esClient) -> {SearchRequest request = new SearchRequest("user");SearchSourceBuilder builder = new SearchSourceBuilder().query(QueryBuilders.matchAllQuery());// 排除或者包括字段String[] includes = {"name", "age"};String[] excludes = {};builder.fetchSource(includes, excludes);request.source(builder);try {SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);SearchHits hits = response.getHits();System.out.println("hits.getTotalHits() = " + hits.getTotalHits());hits.forEach(hit -> {System.out.println("hit.getSourceAsString() = " + hit.getSourceAsString());});} catch (IOException e) {throw new RuntimeException(e);}});}

5.组合查询

    /*** 组合查询*/@Testpublic void combinedQueries() {EsUtil.es((esClient) -> {SearchRequest request = new SearchRequest("user");SearchSourceBuilder builder = new SearchSourceBuilder();// 组合查询// BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();// // 性别必须是男// boolQueryBuilder.must(QueryBuilders.matchQuery("sex", "男"));// // 年龄可以是22或者23// boolQueryBuilder.should(QueryBuilders.matchQuery("age", "22"));// boolQueryBuilder.should(QueryBuilders.matchQuery("age", "23"));// // 至少一个 should 条件必须满足// boolQueryBuilder.minimumShouldMatch(1);// builder.query(boolQueryBuilder);// 范围查询，年龄大于等于21小于等于22RangeQueryBuilder rangeQueryBuilder = QueryBuilders.rangeQuery("age").gte(21).lte(22);builder.query(rangeQueryBuilder);request.source(builder);try {SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);SearchHits hits = response.getHits();System.out.println("hits.getTotalHits() = " + hits.getTotalHits());hits.forEach(hit -> {System.out.println("hit.getSourceAsString() = " + hit.getSourceAsString());});} catch (IOException e) {throw new RuntimeException(e);}});}

6.高亮查询

    /*** 高亮查询*/@Testpublic void highlightedQueries() {EsUtil.es((esClient) -> {SearchRequest request = new SearchRequest("user");SearchSourceBuilder builder = new SearchSourceBuilder();// 高亮查询，对name进行高亮builder.query(QueryBuilders.matchQuery("name", "李四"));HighlightBuilder highlightBuilder = new HighlightBuilder();highlightBuilder.field("name");highlightBuilder.preTags("<font color='red'>");highlightBuilder.postTags("</font>");builder.highlighter(highlightBuilder);request.source(builder);try {SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);SearchHits hits = response.getHits();System.out.println("hits.getTotalHits() = " + hits.getTotalHits());hits.forEach(hit -> {System.out.println("hit.getSourceAsString() = " + hit.getSourceAsString());System.out.println("hit.getHighlightFields() = " + hit.getHighlightFields());});} catch (IOException e) {throw new RuntimeException(e);}});}

7.聚合查询

    /*** 聚合查询*/@Testpublic void aggregateSearch() {EsUtil.es((esClient) -> {SearchRequest request = new SearchRequest("user");SearchSourceBuilder builder = new SearchSourceBuilder();// 聚合操作求最大年龄// MaxAggregationBuilder maxAggregationBuilder = AggregationBuilders.max("maxAge").field("age");// builder.aggregation(maxAggregationBuilder);// 对年龄进行分组TermsAggregationBuilder ageGroup = AggregationBuilders.terms("ageGroup").field("age");builder.aggregation(ageGroup);request.source(builder);try {SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);SearchHits hits = response.getHits();System.out.println("hits.getTotalHits() = " + hits.getTotalHits());hits.forEach(hit -> {System.out.println("hit.getSourceAsString() = " + hit.getSourceAsString());});} catch (IOException e) {throw new RuntimeException(e);}});}