ElasticSearch 学习笔记总结

Posted IT_Holmes

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文章目录

一、ES JavaAPI 环境准备

第一步：创建maven项目，引入相关依赖。

<!-- elasticsearch的核心依赖 -->
<dependency>
    <groupId>org.elasticsearch</groupId>
    <artifactId>elasticsearch</artifactId>
    <version>7.8.0</version>
</dependency>
<!-- elasticsearch的客户端 high-level另外一种组件。 -->
<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>
<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.12</version>
</dependency>

第二步：构建相关API客户端。

package com.itholmes.es.test;

import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;

public class ESTest_Client 

    public static void main(String[] args) throws Exception 
        // 创建ES客户端
        RestHighLevelClient restHighLevelClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost",9200,"http"))
        );
        // 关闭ES客户端
        restHighLevelClient.close();

二、ES JavaAPI 索引

1. 索引 创建

http://127.0.0.1:9200/_cat/indices?v 测试使用

package com.itholmes.es.test;

import org.apache.http.HttpHost;
import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;

public class ESTest_Client 
    public static void main(String[] args) throws Exception 
        // 创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("127.0.0.1",9200,"http"))
        );
        // 创建索引
        CreateIndexRequest request = new CreateIndexRequest("user1");
        CreateIndexResponse createIndexResponse = esClient.indices().create(request, RequestOptions.DEFAULT);
        // 响应状态
        boolean acknowledged = createIndexResponse.isAcknowledged();
        System.out.println("索引操作：" + acknowledged);
        // 关闭ES客户端
        esClient.close();

2. 索引 查找

package com.itholmes.es.test;

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;

public class ESTest_Client_Search 
    public static void main(String[] args) throws Exception 
        // 创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("127.0.0.1",9200,"http"))
        );
        // 查询索引
        GetIndexRequest request = new GetIndexRequest("user1");
        GetIndexResponse getIndexResponse = esClient.indices().get(request, RequestOptions.DEFAULT);
        // 响应状态
        System.out.println(getIndexResponse.getAliases());
        System.out.println(getIndexResponse.getMappings());
        System.out.println(getIndexResponse.getSettings());
        // 关闭ES客户端
        esClient.close();

3. 索引 删除

package com.itholmes.es.test;

import org.apache.http.HttpHost;
import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.action.support.master.AcknowledgedResponse;
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;

public class ESTest_Client_Delete 
    public static void main(String[] args) throws Exception 
        // 创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("127.0.0.1",9200,"http"))
        );
        // 删除索引
        DeleteIndexRequest request = new DeleteIndexRequest("user");
        AcknowledgedResponse delete = esClient.indices().delete(request, RequestOptions.DEFAULT);
        System.out.println("响应是否成功" + delete.isAcknowledged());
        // 关闭ES客户端
        esClient.close();

三、ES JavaAPI 文档

1. 文档 创建

http://127.0.0.1:9200/user/_doc/1001 测试使用。

package com.itholmes.es.test;

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;

public class ESTest_Client_Insert 
    public static void main(String[] args) throws Exception 
        // 创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("127.0.0.1",9200,"http"))
        );
        // 插入数据
        IndexRequest request = new IndexRequest();
        request.index("user").id("1001");
        User user = new User();
        user.setName("zhangsan");
        user.setAge(30);
        user.setSex("男");

        // 向ES插入数据，必须讲数据转换为JSON格式
        ObjectMapper mapper = new ObjectMapper();
        String userJson = mapper.writeValueAsString(user);

        // 放入数据，并且告诉请求的类型
        request.source(userJson, XContentType.JSON);
        // 查询
        IndexResponse response = esClient.index(request, RequestOptions.DEFAULT);
        // 查看结果 （Shard分片）
        System.out.println(response.getResult());
        // 关闭ES客户端
        esClient.close();

2. 文档 修改

package com.itholmes.es.test;

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;

public class ESTest_Dos_Update 
    public static void main(String[] args) throws Exception 
        // 创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("127.0.0.1", 9200, "http"))
        );
        // 修改数据
        UpdateRequest request = new UpdateRequest();
        // 哪个索引，哪个id主键
        request.index("user").id("1001");
        request.doc(XContentType.JSON,"sex","女");
        UpdateResponse response = esClient.update(request, RequestOptions.DEFAULT);
        System.out.println(response.getResult());
        // 关闭ES客户端
        esClient.close();

3. 文档 查询

package com.itholmes.es.test;

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;

public class ESTest_Dos_Get 
    public static void main(String[] args) throws Exception 
        // 创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("127.0.0.1", 9200, "http"))
        );
        // 查询文档
        GetRequest request = new GetRequest();
        request.index("user").id("1001");
        GetResponse response = esClient.get(request, RequestOptions.DEFAULT);
        System.out.println(response.getSourceAsString());
        // 关闭ES客户端
        esClient.close();

4. 文档 删除

package com.itholmes.es.test;

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;

public class ESTest_Dos_Delete 
    public static void main(String[] args) throws Exception 
        // 创建ES客户端
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("127.0.0.1", 9200, "http"))
        );
        DeleteRequest request = new DeleteRequest();
        request.index("user").id("1001");
        // 删除文档
        DeleteResponse delete = esClient.delete(request, RequestOptions.DEFAULT);
        System.out.println(delete.toString());
        // 关闭ES客户端
        esClient.close();

4. 文档 批量新增 和 批量删除

package com.itholmes.es.test;

import org.apache.http.HttpHost以上是关于ElasticSearch 学习笔记总结的主要内容，如果未能解决你的问题，请参考以下文章
 

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