【elastic search】JAVA操作elastic search

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目录

1.环境准备

2.ES JAVA API

3.Spring Boot操作ES

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1.环境准备

本文是作者ES系列的第三篇文章，关于ES的核心概念移步：

https://bugman.blog.csdn.net/article/details/135342256?spm=1001.2014.3001.5502

关于ES的下载安装教程以及基本使用，移步：

https://bugman.blog.csdn.net/article/details/135342256?spm=1001.2014.3001.5502

在前文中，我们已经搭建好了一个es+kibana的基础环境，本文将继续使用该环境，演示JAVA操作es。

2.ES JAVA API

Elasticsearch Rest High Level Client 是 Elasticsearch 官方提供的一个 Java 客户端库，用于与 Elasticsearch 进行交互。这个客户端库是基于 REST 风格的 HTTP 协议，与 Elasticsearch 进行通信，提供了更高级别的抽象，使得开发者可以更方便地使用 Java 代码与 Elasticsearch 进行交互。

依赖：

<dependency>    <groupId>org.elasticsearch</groupId>    <artifactId>elasticsearch</artifactId>    <version>7.17.3</version></dependency><dependency>    <groupId>org.elasticsearch.client</groupId>    <artifactId>elasticsearch-rest-high-level-client</artifactId>    <version>7.17.3</version></dependency><dependency>    <groupId>org.apache.logging.log4j</groupId>    <artifactId>log4j-core</artifactId>    <version>2.10.0</version></dependency><dependency>    <groupId>junit</groupId>    <artifactId>junit</artifactId>    <version>4.12</version></dependency><dependency>    <groupId>com.alibaba.fastjson2</groupId>    <artifactId>fastjson2</artifactId>    <version>2.0.45</version></dependency>

其实Rest High Level Client的使用逻辑一共就分散步：

拼json创建requestclient执行request

创建client：

RestHighLevelClient restHighLevelClient = new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.1",9200,"http")));

创建索引：

@Test    public void createIndex() throws IOException {        //1.拼json        //settings        Settings.Builder settings = Settings.builder()                .put("number_of_shards", 3)                .put("number_of_replicas", 1);        //mappings        XContentBuilder mappings = JsonXContent.contentBuilder().                startObject().                    startObject("properties").                    startObject("name").                        field("type", "text").                    endObject().                    startObject("age").                        field("type", "integer").                    endObject().                    endObject().                endObject();        //2.创建request        CreateIndexRequest createIndexRequest = new CreateIndexRequest("person").settings(settings).mapping(mappings);        //3.client执行request        restHighLevelClient.indices().create(createIndexRequest, RequestOptions.DEFAULT);    }

创建文档：

@Test    public void createDoc() throws IOException {        Person person=new Person("1","zou",20);        JSONObject json = JSONObject.from(person);        System.out.println(json);        IndexRequest request=new IndexRequest("person",null,person.getId().toString());        request.source(json, XContentType.JSON);        IndexResponse response = restHighLevelClient.index(request, RequestOptions.DEFAULT);        System.out.println(response);    }

响应结果：

修改文档：

@Test    public void updateDoc() throws IOException {        HashMap<String, Object> doc = new HashMap();        doc.put("name","张三");        String docId="1";        UpdateRequest request=new UpdateRequest("person",null,docId);        UpdateResponse response = restHighLevelClient.update(request, RequestOptions.DEFAULT);        System.out.println(response.getResult().toString());    }

删除文档：

@Test    public void deleteDoc() throws IOException {        DeleteRequest request=new DeleteRequest("person",null,"1");        DeleteResponse response = restHighLevelClient.delete(request, RequestOptions.DEFAULT);        System.out.println(response.getResult().toString());    }

响应结果：

搜索示例：

import org.elasticsearch.action.search.SearchRequest;import org.elasticsearch.action.search.SearchResponse;import org.elasticsearch.client.RequestOptions;import org.elasticsearch.client.RestHighLevelClient;import org.elasticsearch.common.unit.TimeValue;import org.elasticsearch.index.query.QueryBuilders;import org.elasticsearch.search.builder.SearchSourceBuilder;import java.io.IOException;public class ElasticsearchSearchExample {    public static void main(String[] args) {        // 创建 RestHighLevelClient 实例，连接到 Elasticsearch 集群        RestHighLevelClient client = new RestHighLevelClient(                RestClient.builder(new HttpHost("localhost", 9200, "http"))        );        // 构建搜索请求        SearchRequest searchRequest = new SearchRequest("your_index"); // 替换为实际的索引名称        // 构建查询条件        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();        searchSourceBuilder.query(QueryBuilders.matchAllQuery()); // 查询所有文档        // 设置一些可选参数        searchSourceBuilder.from(0); // 设置起始索引，默认为0        searchSourceBuilder.size(10); // 设置返回结果的数量，默认为10        searchSourceBuilder.timeout(new TimeValue(5000)); // 设置超时时间，默认为1分钟        // 将查询条件设置到搜索请求中        searchRequest.source(searchSourceBuilder);        try {            // 执行搜索请求            SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);            // 处理搜索响应            System.out.println("Search took: " + searchResponse.getTook());            // 获取搜索结果            SearchHits hits = searchResponse.getHits();            System.out.println("Total hits: " + hits.getTotalHits().value);            // 遍历搜索结果            for (SearchHit hit : hits.getHits()) {                System.out.println("Document ID: " + hit.getId());                System.out.println("Source: " + hit.getSourceAsString());            }        } catch (IOException e) {            // 处理异常            e.printStackTrace();        } finally {            try {                // 关闭客户端连接                client.close();            } catch (IOException e) {                // 处理关闭连接异常                e.printStackTrace();            }        }    }}

请注意，上述示例中的 your_index 应该替换为你实际的 Elasticsearch 索引名称。这个示例使用了简单的 matchAllQuery，你可以根据实际需求构建更复杂的查询条件。在搜索响应中，你可以获取到搜索的结果以及相关的元数据。

3.Spring Boot操作ES

在 Spring Boot 中操作 Elasticsearch 通常使用 Spring Data Elasticsearch，以标准的JPA的模式来操作ES。

依赖：

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.6.x</version> <!-- 选择一个与Elasticsearch 7.17.3兼容的Spring Boot版本 -->
</parent>

<dependencies>
    <!-- Spring Boot Starter Web -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <!-- Spring Data Elasticsearch -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
    </dependency>

    <!-- Spring Boot Starter Test (for testing) -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>
application.properties配置：

spring.data.elasticsearch.cluster-nodes=localhost:9200

实体类：

import org.springframework.data.annotation.Id;import org.springframework.data.elasticsearch.annotations.Document;import org.springframework.data.elasticsearch.annotations.Field;import org.springframework.data.elasticsearch.annotations.FieldType;import java.util.Date;@Document(indexName = "blogpost_index")public class BlogPost {    @Id    private String id;    @Field(type = FieldType.Text)    private String title;    @Field(type = FieldType.Text)    private String content;    @Field(type = FieldType.Keyword)    private String author;    @Field(type = FieldType.Date)    private Date publishDate;    // 构造函数、getter和setter    public BlogPost() {    }    public BlogPost(String id, String title, String content, String author, Date publishDate) {        this.id = id;        this.title = title;        this.content = content;        this.author = author;        this.publishDate = publishDate;    }    // 省略 getter 和 setter 方法}

dao层：

import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;public interface BlogPostRepository extends ElasticsearchRepository<BlogPost, String> {    // 你可以在这里定义自定义查询方法}

service层：

import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import java.util.List;import java.util.Optional;@Servicepublic class BlogPostService {    private final BlogPostRepository blogPostRepository;    @Autowired    public BlogPostService(BlogPostRepository blogPostRepository) {        this.blogPostRepository = blogPostRepository;    }    public BlogPost save(BlogPost blogPost) {        return blogPostRepository.save(blogPost);    }    public Optional<BlogPost> findById(String id) {        return blogPostRepository.findById(id);    }    public List<BlogPost> findAll() {        return (List<BlogPost>) blogPostRepository.findAll();    }    public void deleteById(String id) {        blogPostRepository.deleteById(id);    }}

 

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本文链接：https://www.kjpai.cn/gushi/2024-03-24/148140.html，文章来源：网络cs，作者：亙句，版权归作者所有，如需转载请注明来源和作者，否则将追究法律责任！