使用Java RestHighLevelClient操作Elasticsearch索引和文档-开发者社区-阿里云

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

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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