ElasticSearch学习

it2024-01-20 63

1. 对Es的初认知，参考链接：

1.1 https://blog.csdn.net/cxu123321/article/details/90339552 1.2 https://blog.csdn.net/JENREY/article/details/81290535?utm_medium=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-1.channel_param&depth_1-utm_source=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-1.channel_param#4.2%20%E5%AE%89%E8%A3%85%E5%B9%B6%E5%90%AF%E5%8A%A8ES

1.3 几个关键概念https://www.cnblogs.com/chy18883701161/archive/2020/04/16/12710574.html

1.4 Elasticsearch官方中文文档 https://www.elastic.co/guide/cn/index.html

2. windows下装Es做测试，参考链接：

2.1 windows环境下elasticsearch安装教程(超详细) https://www.cnblogs.com/hualess/p/11540477.html

2.2 Elasticsearch集群 windows下部署ES集群,多台服务器 https://www.cnblogs.com/zhaixingzhu/p/12562755.html

3. Es版本认知，参考链接：

3.1 在 5.X 版本中，一个 index 下可以创建多个 type；在 6.X 版本中，一个 index 下只能存在一个 type；在 7.X 版本中，直接去除了 type 的概念，就是说 index 不再会有 type。

3.2 为什么ElasticSearch要在7.X版本去掉type?https://blog.csdn.net/zjx546391707/article/details/78631394?utm_medium=distribute.pc_relevant_t0.none-task-blog-BlogCommendFromMachineLearnPai2-1.channel_param&depth_1-utm_source=distribute.pc_relevant_t0.none-task-blog-BlogCommendFromMachineLearnPai2-1.channel_param

3.3 ES7变更后解决方案 https://blog.csdn.net/qq_34182808/article/details/99620548

4. 搭建项目，简单的增删改查

代码参考链接：

4.1. Elasticsearch应用七：ES Java客户端-Elasticsearch Java clienthttps://blog.csdn.net/lch520baby/article/details/89183693?utm_medium=distribute.pc_relevant_t0.none-task-blog-BlogCommendFromMachineLearnPai2-1.channel_param&depth_1-utm_source=distribute.pc_relevant_t0.none-task-blog-BlogCommendFromMachineLearnPai2-1.channel_param

4.2 es-RestHighLevelClient增删改查https://www.cnblogs.com/javallh/p/13790486.html

4.3 Elasticsearch修改mapping解决方案https://blog.csdn.net/lln_avaj/article/details/85048633

4.4 sprintboot集成eshttps://my.oschina.net/u/2449415/blog/1840751

4.5 使用eclipsec创建springboot项目https://blog.csdn.net/qq_38555490/article/details/90263684

5. RestHighLevelClient方式的简单实现（看网上资料说tranport的方式在8.x后不在支持，所以没有研究另一种方式）

5.1使用到的jar包：

5.2安装Es用到的工具：

5.2.1 ElasticSearch下载地址： https://www.elastic.co/downloads/elasticsearch

5.2.2 下载head插件: 网址:https://github.com/mobz/elasticsearch-head下载安装包

5.3 代码实现：

package com.aura.utils; import java.io.IOException; import java.util.HashMap; import java.util.Map; import org.apache.http.HttpHost; import org.elasticsearch.ElasticsearchException; import org.elasticsearch.action.DocWriteResponse; import org.elasticsearch.action.DocWriteResponse.Result; import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest; import org.elasticsearch.action.delete.DeleteRequest; import org.elasticsearch.action.delete.DeleteResponse; import org.elasticsearch.action.get.GetRequest; import org.elasticsearch.action.get.GetResponse; import org.elasticsearch.action.index.IndexRequest; import org.elasticsearch.action.index.IndexResponse; import org.elasticsearch.action.support.master.AcknowledgedResponse; import org.elasticsearch.action.support.replication.ReplicationResponse; 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.client.indices.CreateIndexRequest; import org.elasticsearch.client.indices.CreateIndexResponse; import org.elasticsearch.client.indices.GetIndexRequest; import org.elasticsearch.client.indices.PutMappingRequest; import org.elasticsearch.common.settings.Settings; import org.elasticsearch.common.settings.Settings.Builder; import org.elasticsearch.common.unit.TimeValue; import org.elasticsearch.common.xcontent.XContentBuilder; import org.elasticsearch.common.xcontent.XContentFactory; import org.elasticsearch.common.xcontent.XContentType; import org.elasticsearch.rest.RestStatus; /** * 参考链接： * https://blog.csdn.net/weixin_39860704/article/details/89497547 * https://www.cnblogs.com/betterwgo/p/11268869.html */ public class EsUtils { public static void main(String[] args) { RestHighLevelClient client = getClient(); CreateIndexRequest request = createIndex("twitter",client); createMapping(request); setOuttimes(request); //同步执行，执行请求，创建索引 // CreateIndexResponse createIndexResponse = null; // try { // createIndexResponse = client.indices().create(request, RequestOptions.DEFAULT); // } catch (IOException e) { // e.printStackTrace(); // } // boolean acknowledged = createIndexResponse.isAcknowledged(); // boolean shardsAcknowledged = createIndexResponse.isShardsAcknowledged(); // System.out.println("acknowledged="+acknowledged); // System.out.println("shardsAcknowledged="+shardsAcknowledged); //删除索引 //deleteIndex("twitter",client); //修改表结构 try { updateMapping("twitter",client); } catch (Exception e1) { e1.printStackTrace(); } //创建Document //createDocument("twitter",client); //查询Document通过id //getDocumentById("twitter","1",client); //修改Document通过id //updateDocumentById("twitter","1",client); //删除Document通过id //removeDocumentById("twitter","1",client); //关闭链接 try { client.close(); } catch (IOException e) { e.printStackTrace(); } } //获取连接 public static RestHighLevelClient getClient() { RestHighLevelClient client = new RestHighLevelClient( RestClient.builder(new HttpHost("localhost", 9200, "http"))); return client; } //创建索引(即创建库) public static CreateIndexRequest createIndex(String indexName,RestHighLevelClient client){ //1. 创建索引请求 CreateIndexRequest request = new CreateIndexRequest(indexName); Builder builder = Settings.builder().put("index.number_of_shards", 3).put("index.number_of_replicas", 1); request.settings(builder); return request; } //删除索引 public static void deleteIndex(String indexName,RestHighLevelClient client) { DeleteIndexRequest request = new DeleteIndexRequest(indexName); AcknowledgedResponse deleteIndexResponse = null; try { deleteIndexResponse = client.indices().delete(request, RequestOptions.DEFAULT); } catch (IOException e) { e.printStackTrace(); } boolean acknowledged = deleteIndexResponse.isAcknowledged(); System.out.println("index删除结果:"+acknowledged); } /** * 判断索引是否存在 * @param indexName * @return * @throws IOException */ public boolean checkIndexExists(String indexName,RestHighLevelClient client) { GetIndexRequest request = new GetIndexRequest(indexName); try { return client.indices().exists(request, RequestOptions.DEFAULT); } catch (IOException e) { System.out.println("判断索引是否存在，操作异常！"); } return false; } //设置mapping(即创建表结构) public static void createMapping(CreateIndexRequest request){ Map<String, Object> message = new HashMap<>(); message.put("type", "text"); Map<String, Object> properties = new HashMap<>(); properties.put("message", message); Map<String, Object> mapping = new HashMap<>(); mapping.put("properties", properties); request.mapping(mapping); } //更新mapping(更新表结构) public static void updateMapping(String indexName,RestHighLevelClient client) throws Exception { PutMappingRequest request = new PutMappingRequest(indexName); XContentBuilder builder = XContentFactory.jsonBuilder(); builder.startObject(); { builder.startObject("properties"); { builder.startObject("message"); { builder.field("type", "text"); } builder.endObject(); builder.startObject("username"); { builder.field("type", "text"); } builder.endObject(); builder.startObject("sex"); { builder.field("type", "text"); } builder.endObject(); } builder.endObject(); } builder.endObject(); request.source(builder); AcknowledgedResponse PutMappingResponse = client.indices().putMapping(request, RequestOptions.DEFAULT); boolean acknowledged = PutMappingResponse.isAcknowledged(); System.out.println("updateMapping结果:"+acknowledged); } //新增Document public static void createDocument(String indextName,RestHighLevelClient client){ // 1、创建索引请求 IndexRequest request = new IndexRequest( indextName, //索引 "_doc", // mapping type "2"); //文档id // 2、准备文档数据 // 方式一：直接给JSON串 String jsonString = "{" + "\"username\":\"张三\"," + "\"sex\":\"男\"," + "\"message\":\"你好啊，hello!\"" + "}"; request.source(jsonString, XContentType.JSON); // 方式二：以map对象来表示文档 /* Map<String, Object> jsonMap = new HashMap<>(); jsonMap.put("username", "张三"); jsonMap.put("message", "你好啊，hello!"); request.source(jsonMap); */ // 方式三：用XContentBuilder来构建文档 /* XContentBuilder builder = XContentFactory.jsonBuilder(); builder.startObject(); { builder.field("username", "张三"); builder.field("message", "你好啊，hello!"); } builder.endObject(); request.source(builder); */ // 方式四：直接用key-value对给出 /* request.source("username", "张三", "message", "你好啊，hello!"); */ //3、其他的一些可选设置 /* request.routing("routing"); //设置routing值 request.timeout(TimeValue.timeValueSeconds(1)); //设置主分片等待时长 request.setRefreshPolicy("wait_for"); //设置重刷新策略 request.version(2); //设置版本号 request.opType(DocWriteRequest.OpType.CREATE); //操作类别 */ //4、发送请求 IndexResponse indexResponse = null; try { // 同步方式 indexResponse = client.index(request,RequestOptions.DEFAULT); } catch(Exception e) { System.out.println("索引异常:"+e); } //5、处理响应 if(indexResponse != null) { String index = indexResponse.getIndex(); String type = indexResponse.getType(); String id = indexResponse.getId(); long version = indexResponse.getVersion(); if (indexResponse.getResult() == DocWriteResponse.Result.CREATED) { System.out.println("新增文档成功，处理逻辑代码写到这里。"); } else if (indexResponse.getResult() == DocWriteResponse.Result.UPDATED) { System.out.println("修改文档成功，处理逻辑代码写到这里。"); } // 分片处理信息 ReplicationResponse.ShardInfo shardInfo = indexResponse.getShardInfo(); if (shardInfo.getTotal() != shardInfo.getSuccessful()) { } // 如果有分片副本失败，可以获得失败原因信息 if (shardInfo.getFailed() > 0) { for (ReplicationResponse.ShardInfo.Failure failure : shardInfo.getFailures()) { String reason = failure.reason(); System.out.println("副本失败原因：" + reason); } } } //异步方式发送索引请求 /*ActionListener<IndexResponse> listener = new ActionListener<IndexResponse>() { @Override public void onResponse(IndexResponse indexResponse) { } @Override public void onFailure(Exception e) { } }; client.indexAsync(request, listener); */ } //更新Document通过id public static void updateDocumentById(String indexName,String id,RestHighLevelClient client){ Map<String,Object> map=new HashMap<>(); map.put("username", "李四"); UpdateRequest updateRequest = new UpdateRequest(indexName,id).doc(map); try { UpdateResponse updateResponse= client.update(updateRequest,RequestOptions.DEFAULT); } catch (IOException e) { System.out.println("updateResponse异常:"+e); } System.out.println("updateDocumentById完成"); } //删除Document通过id public static String removeDocumentById(String indexName,String id,RestHighLevelClient client) { DeleteRequest deleteRequest = new DeleteRequest(indexName, id); // 操作ES DeleteResponse deleteResponse = null; try { deleteResponse = client.delete(deleteRequest, RequestOptions.DEFAULT); } catch (IOException e) { System.out.println("es删除异常："+e); } Result resultResponse = deleteResponse.getResult(); String result = resultResponse.toString(); System.out.println("removeDocumentById结果:"+result); return result; } //查询Document public static String getDocumentById(String indexName,String id,RestHighLevelClient client) { GetRequest getRequest = new GetRequest(indexName, id); GetResponse getResponse = null; try { getResponse = client.get(getRequest, RequestOptions.DEFAULT); } catch (Exception e) { System.out.println("es查询异常:"+e); } String result = getResponse.getSourceAsString(); System.out.println("getDocumentById结果："+result); return result; } //设置超时时间 public static void setOuttimes(CreateIndexRequest request) { request.setTimeout(TimeValue.timeValueMinutes(2)); request.setMasterTimeout(TimeValue.timeValueMinutes(1)); } }

总结：mapping结构不支持修改和删除，如果中途想要修改或删除某个字段名，只能想别的办法

Es的批量增删改查，此处暂时没研究，后续跟新

完整测试项目地址：https://gitee.com/mayun-lin/elasticSearchTest.git

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