Elasticsearch——使用Java API实现ES中的索引、映射、文档操作（上）-阿里云开发者社区

在上一篇文章中，对ES中的创建/查看/删除索引、创建定义映射、创建/查看/修改/删除文档的这些操作有了一定的了解认识，但是是通过Postman + JSON串的方法来实现的。文章链接：https://blog.csdn.net/weixin_43823808/article/details/119911746

那么，这篇文章，仍然是对ES中的索引、映射、文档进行操作，只是方法换成了Java API。

2.案例详解

首先需要创建一个maven工程，必然要添加ES相关的依赖。

同时双击ES安装目录的bin目录下的elasticsearch.bat ，先启动ES服务端。

        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>7.8.0</version>
        </dependency>
        <!-- elasticsearch 的客户端 -->
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
            <version>7.8.0</version>
        </dependency>
        <!-- elasticsearch 依赖 2.x 的 log4j -->
        <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>
        <!-- junit 单元测试 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>

2.1 创建ES客户端：完成与ES服务端的连接

后面的一二十个案例都是依照这个模板代码来的。

package com.szh.es;
import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import java.io.IOException;
/**
 *
 */
public class ESTestClient {
    public static void main(String[] args) throws IOException {
        //创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost",9200,"http"))
        );
        //关闭ES客户端
        esClient.close();
    }
}

2.2 创建索引

package com.szh.es;
import org.apache.http.HttpHost;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.indices.CreateIndexRequest;
import org.elasticsearch.client.indices.CreateIndexResponse;
import java.io.IOException;
/**
 *
 */
public class ESTestIndexCreate {
    public static void main(String[] args) throws IOException {
        //创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost",9200,"http"))
        );
        //创建索引 --- 请求对象
        CreateIndexRequest request = new CreateIndexRequest("user");
        //发送请求 --- 获取响应
        CreateIndexResponse response = esClient.indices().create(request, RequestOptions.DEFAULT);
        //响应状态
        boolean acknowledged = response.isAcknowledged();
        System.out.println("索引操作：" + acknowledged);
        //关闭ES客户端
        esClient.close();
    }
}

2.3 查看索引

package com.szh.es;
import org.apache.http.HttpHost;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.indices.GetIndexRequest;
import org.elasticsearch.client.indices.GetIndexResponse;
import java.io.IOException;
/**
 *
 */
public class ESTestIndexSearch {
    public static void main(String[] args) throws IOException {
        //创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost",9200,"http"))
        );
        //查询索引 --- 请求对象
        GetIndexRequest request = new GetIndexRequest("user");
        //发送请求 --- 获取响应
        GetIndexResponse response = esClient.indices().get(request, RequestOptions.DEFAULT);
        //响应状态
        System.out.println(response.getAliases());
        System.out.println(response.getMappings());
        System.out.println(response.getSettings());
        //关闭ES客户端
        esClient.close();
    }
}

2.4 删除索引

package com.szh.es;
import org.apache.http.HttpHost;
import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
import org.elasticsearch.action.support.master.AcknowledgedResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import java.io.IOException;
/**
 *
 */
public class ESTestIndexDelete {
    public static void main(String[] args) throws IOException {
        //创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost",9200,"http"))
        );
        //删除索引 --- 请求对象
        DeleteIndexRequest request = new DeleteIndexRequest("user");
        //发送请求 --- 获取响应
        AcknowledgedResponse response = esClient.indices().delete(request,RequestOptions.DEFAULT);
        //响应状态
        System.out.println(response.isAcknowledged());
        //关闭ES客户端
        esClient.close();
    }
}

2.5 创建文档

索引有了，就相当于有了数据库。接下来就需要向数据库中建表、添加数据。建表自然要有表结构（有哪些属性、这些属性分别都是什么数据类型），也就是ES中的映射，在Java代码中就可以采用实体类来实现。

package com.szh.es;
/**
 *
 */
public class User {
    private String name;
    private String sex;
    private Integer age;
    //getter and setter
}

package com.szh.es;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.http.HttpHost;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;
import java.io.IOException;
/**
 *
 */
public class ESTestDocInsert {
    public static void main(String[] args) throws IOException {
        //创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost",9200,"http"))
        );
        //创建文档 --- 请求对象
        IndexRequest request = new IndexRequest();
        //设置索引及索引中文档的唯一性标识id（如果不指定，则ES会默认随机生成一个id）
        request.index("user").id("1001");
        //创建数据对象（文档内容）
        User user = new User();
        user.setName("张起灵");
        user.setSex("man");
        user.setAge(21);
        //向ES中插入数据，必须将数据格式转换为JSON
        ObjectMapper objectMapper = new ObjectMapper();
        String userJson = objectMapper.writeValueAsString(user);
        request.source(userJson, XContentType.JSON);
        //发送请求 --- 获取响应
        IndexResponse response = esClient.index(request, RequestOptions.DEFAULT);
        System.out.println(response.getResult());
        //关闭ES客户端
        esClient.close();
    }
}

2.6 修改文档

package com.szh.es;
import org.apache.http.HttpHost;
import org.elasticsearch.action.update.UpdateRequest;
import org.elasticsearch.action.update.UpdateResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;
import java.io.IOException;
/**
 *
 */
public class ESTestDocUpdate {
    public static void main(String[] args) throws IOException {
        //创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost",9200,"http"))
        );
        //修改文档 --- 请求对象
        UpdateRequest request = new UpdateRequest();
        //配置修改参数 --- 表示要修改user索引中id为1001的文档内容
        request.index("user").id("1001");
        //将修改后的内容，以JSON格式写入请求体中
        request.doc(XContentType.JSON,"age",18);
        //发送请求 --- 获取响应
        UpdateResponse response = esClient.update(request,RequestOptions.DEFAULT);
        System.out.println(response.getResult());
        //关闭ES客户端
        esClient.close();
    }
}

2.7 查看文档

package com.szh.es;
import org.apache.http.HttpHost;
import org.elasticsearch.action.get.GetRequest;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import java.io.IOException;
/**
 *
 */
public class ESTestDocSearch {
    public static void main(String[] args) throws IOException {
        //创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost",9200,"http"))
        );
        //查询文档 --- 请求对象
        GetRequest request = new GetRequest();
        //设置请求参数 --- 表示要查询user索引中id为1001的文档内容
        request.index("user").id("1001");
        //发送请求 --- 获取响应
        GetResponse response = esClient.get(request,RequestOptions.DEFAULT);
        System.out.println(response.getSourceAsString());
        //关闭ES客户端
        esClient.close();
    }
}

2.8 删除文档

package com.szh.es;
import org.apache.http.HttpHost;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import java.io.IOException;
/**
 *
 */
public class ESTestDocDelete {
    public static void main(String[] args) throws IOException {
        //创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost",9200,"http"))
        );
        //删除文档 --- 请求对象
        DeleteRequest request = new DeleteRequest();
        //设置请求参数 --- 表示要删除user索引中id为1001的文档
        request.index("user").id("1001");
        //发送请求 --- 获取响应
        DeleteResponse response = esClient.delete(request,RequestOptions.DEFAULT);
        System.out.println(response.getResult());
        //关闭ES客户端
        esClient.close();
    }
}

2.9 批量创建文档

package com.szh.es;
import org.apache.http.HttpHost;
import org.elasticsearch.action.bulk.BulkRequest;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;
import java.io.IOException;
/**
 *
 */
public class ESTestDocInsertBatch {
    public static void main(String[] args) throws IOException {
        //创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost",9200,"http"))
        );
        //批量新增文档 --- 请求对象
        BulkRequest request = new BulkRequest();
        //以JSON格式批量新增文档 --- 存入请求体中
        request.add(new IndexRequest().index("user").id("1001").source(XContentType.JSON, "name", "张起灵","sex","boy","age",21));
        request.add(new IndexRequest().index("user").id("1002").source(XContentType.JSON, "name", "小哥","sex","boy","age",18));
        request.add(new IndexRequest().index("user").id("1003").source(XContentType.JSON, "name", "小宋","sex","boy","age",20));
        //发送请求 --- 获取响应
        BulkResponse response = esClient.bulk(request, RequestOptions.DEFAULT);
        System.out.println(response.getTook());
        //关闭ES客户端
        esClient.close();
    }
}

Elasticsearch——使用Java API实现ES中的索引、映射、文档操作（上）

文章目录：

1.开篇

2.案例详解

2.1 创建ES客户端：完成与ES服务端的连接

2.2 创建索引

2.3 查看索引

2.4 删除索引

2.5 创建文档

2.6 修改文档

2.7 查看文档

2.8 删除文档

2.9 批量创建文档

热门文章

最新文章

相关课程

相关电子书

相关实验场景

探索云世界

热门

云计算

大数据

云原生

人工智能

数据库

开发与运维

活动广场

任务中心

训练营

直播

乘风者计划

下载

镜像站

技术资料

Elasticsearch——使用Java API实现ES中的索引、映射、文档操作（上）

文章目录：

1.开篇

2.案例详解

2.1 创建ES客户端：完成与ES服务端的连接

2.2 创建索引

2.3 查看索引

2.4 删除索引

2.5 创建文档

2.6 修改文档

2.7 查看文档

2.8 删除文档

2.9 批量创建文档

热门文章

最新文章

相关课程

相关电子书

相关实验场景