Notas del estudio de Elasticsearch (7) cliente Java de Elasticsearch

Others 2021-03-28 22:47:47 views: null

Tabla de contenido

Introducción a ES Client

ES es un servicio, usando estructura C / S

Revisar la arquitectura de ES

Métodos de conexión de cliente admitidos por ES

ES proporciona múltiples clientes de lenguaje de programación

Cliente REST de Java

ES proporciona dos versiones de cliente JAVA REST

Descripción del cliente REST de bajo nivel de Java

Descripción del cliente REST de alto nivel de Java

Nota de compatibilidad

Experto en cliente REST de alto nivel de Java 集成

Inicialización del cliente REST de alto nivel de Java

API

QueryBuilder correspondiente a varias consultas

AggregationBuilder correspondiente a varias agregaciones

Cliente Java

Descripción del cliente Java

Enlace de aprendizaje oficial

Nota de compatibilidad

Integración maven del cliente Java

Descripción del registrador del cliente Java

Cliente inicial

Configuración inicial del cliente Descripción del parámetro disponible

API de documentos API de manipulación de documentos

API de búsqueda

Ejemplo de código: dirección es-java-client

Enlace de aprendizaje Spring Data Elasticsearch

Introducción a ES Client

ES es un servicio, usando estructura C / S

Revisar la arquitectura de ES

Métodos de conexión de cliente admitidos por ES

  •  API REST, puerto 9200  
  • Puerto de conexión de transporte 9300

ES proporciona múltiples clientes de lenguaje de programación

Enlace de aprendizaje de API del cliente https://www.elastic.co/guide/en/elasticsearch/client/index.html

Cliente REST de Java

ES proporciona dos versiones de cliente JAVA REST

  •   Cliente REST de bajo nivel de Java: un cliente REST de bajo nivel que interactúa con el clúster a través de http. El usuario debe organizar la cadena JSON de solicitud por sí mismo y analizar la cadena JSON de respuesta. Compatible con todas las versiones ES.
  •   Cliente REST de alto nivel de Java: un cliente REST de alto nivel, basado en el cliente REST de bajo nivel, que agrega API relacionadas, como solicitudes de clasificación y respuestas de análisis.

Descripción del cliente REST de bajo nivel de Java

  •  Para conocer las características, consulte la introducción y el uso de maven:

            https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-low.html

  •  Documento de API, consulte:

             https://artifacts.elastic.co/javadoc/org/elasticsearch/client/elasticsearch-rest-client/6.2.4/index.html.

Descripción del cliente REST de alto nivel de Java

  •   Se ha agregado desde 6.0.0, y el propósito es procesar solicitudes y respuestas de una manera orientada a objetos de Java.
  •   Cada API admite métodos sincrónicos y asincrónicos, y el método sincrónico devuelve directamente un objeto de resultado. El método asincrónico tiene el sufijo async y el resultado se notifica a través del parámetro de escucha.
  •   El cliente Java REST avanzado depende del proyecto principal de Elasticsearch

Nota de compatibilidad

  •   Depende del proyecto principal java1.8 y Elasticsearch
  •   Utilice la versión del cliente que sea coherente con la versión del servidor ES

Experto en cliente REST de alto nivel de Java 集成

<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-high-level-client</artifactId>
    <version>6.2.4</version>
</dependency>

Inicialización del cliente REST de alto nivel de Java

RestHighLevelClient client = new RestHighLevelClient(
        RestClient.builder(
                new HttpHost("localhost", 9200, "http"),
                new HttpHost("localhost", 9201, "http")));

Dadas varias direcciones de nodo en el clúster, equilibre la carga del cliente para enviar solicitudes a este conjunto de direcciones de nodo

El cliente ya no está en uso, recuerde cerrarlo.

client.close();

API

Para obtener ejemplos de API y uso, consulte:

https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high-supported-apis.html

  • Crear índice
package com.dongnao.es_hrset_client;

import java.io.IOException;

import org.elasticsearch.action.admin.indices.alias.Alias;
import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.xcontent.XContentType;

public class CreateIndexDemo {

	public static void main(String[] args) {
		try (RestHighLevelClient client = InitDemo.getClient();) {

			// 1、创建 创建索引request
			CreateIndexRequest request = new CreateIndexRequest("mess");

			// 2、设置索引的settings
			request.settings(Settings.builder().put("index.number_of_shards", 3) // 分片数
					.put("index.number_of_replicas", 2) // 副本数
					.put("analysis.analyzer.default.tokenizer", "ik_smart") // 默认分词器
			);

			// 3、设置索引的mappings
			request.mapping("_doc",
					"  {\n" +
				    "    \"tweet\": {\n" +
				    "      \"properties\": {\n" +
				    "        \"message\": {\n" +
				    "          \"type\": \"text\"\n" +
				    "        }\n" +
				    "      }\n" +
				    "    }\n" +
				    "  }",
					XContentType.JSON);

			// 4、 设置索引的别名
			request.alias(new Alias("mmm"));

			// 5、 发送请求
			// 5.1 同步方式发送请求
			CreateIndexResponse createIndexResponse = client.indices()
					.create(request);

			// 6、处理响应
			boolean acknowledged = createIndexResponse.isAcknowledged();
			boolean shardsAcknowledged = createIndexResponse
					.isShardsAcknowledged();
			System.out.println("acknowledged = " + acknowledged);
			System.out.println("shardsAcknowledged = " + shardsAcknowledged);

			// 5.1 异步方式发送请求
			/*ActionListener<CreateIndexResponse> listener = new ActionListener<CreateIndexResponse>() {
				@Override
				public void onResponse(
						CreateIndexResponse createIndexResponse) {
					// 6、处理响应
					boolean acknowledged = createIndexResponse.isAcknowledged();
					boolean shardsAcknowledged = createIndexResponse
							.isShardsAcknowledged();
					System.out.println("acknowledged = " + acknowledged);
					System.out.println(
							"shardsAcknowledged = " + shardsAcknowledged);
				}

				@Override
				public void onFailure(Exception e) {
					System.out.println("创建索引异常：" + e.getMessage());
				}
			};

			client.indices().createAsync(request, listener);
			*/
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}
  • documento índice
package com.dongnao.es_hrset_client;

import java.io.IOException;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.action.DocWriteResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.support.replication.ReplicationResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.rest.RestStatus;

public class IndexDocumentDemo {
	
	private static Logger logger = LogManager.getRootLogger();  

	public static void main(String[] args) {
		try (RestHighLevelClient client = InitDemo.getClient();) {
			// 1、创建索引请求
			IndexRequest request = new IndexRequest(
			        "mess",   //索引
			        "_doc",     // mapping type
			        "1");     //文档id  
			
			// 2、准备文档数据
			// 方式一：直接给JSON串
			String jsonString = "{" +
			        "\"user\":\"kimchy\"," +
			        "\"postDate\":\"2013-01-30\"," +
			        "\"message\":\"trying out Elasticsearch\"" +
			        "}";
			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("user", "kimchy");
			jsonMap.put("postDate", new Date());
			jsonMap.put("message", "trying out Elasticsearch");
			request.source(jsonMap); 
			*/
			
			// 方式三：用XContentBuilder来构建文档
			/*
			XContentBuilder builder = XContentFactory.jsonBuilder();
			builder.startObject();
			{
			    builder.field("user", "kimchy");
			    builder.field("postDate", new Date());
			    builder.field("message", "trying out Elasticsearch");
			}
			builder.endObject();
			request.source(builder); 
			*/
			
			// 方式四：直接用key-value对给出
			/*
			request.source("user", "kimchy",
			                "postDate", new Date(),
			                "message", "trying out Elasticsearch");
			*/
			
			//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);			
			} catch(ElasticsearchException e) {
				// 捕获，并处理异常
				//判断是否版本冲突、create但文档已存在冲突
			    if (e.status() == RestStatus.CONFLICT) {
			    	logger.error("冲突了，请在此写冲突处理逻辑！\n" + e.getDetailedMessage());
			    }
			    
			    logger.error("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);
			*/
			
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}
  • obtener documento
package com.dongnao.es_hrset_client;

import java.io.IOException;
import java.util.Map;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.action.get.GetRequest;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.Strings;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.fetch.subphase.FetchSourceContext;

public class GetDocumentDemo {
	
	private static Logger logger = LogManager.getRootLogger();  

	public static void main(String[] args) {
		try (RestHighLevelClient client = InitDemo.getClient();) {
			// 1、创建索引请求
			GetRequest request = new GetRequest(
			        "mess",   //索引
			        "_doc",     // mapping type
			        "1");     //文档id  
			
			// 2、可选的设置
			//request.routing("routing");
			//request.version(2);
			
			//request.fetchSourceContext(new FetchSourceContext(false)); //是否获取_source字段
			//选择返回的字段
			String[] includes = new String[]{"message", "*Date"};
			String[] excludes = Strings.EMPTY_ARRAY;
			FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes);
			request.fetchSourceContext(fetchSourceContext); 
			
			//也可写成这样
			/*String[] includes = Strings.EMPTY_ARRAY;
			String[] excludes = new String[]{"message"};
			FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes);
			request.fetchSourceContext(fetchSourceContext);*/
			
			
			// 取stored字段
			/*request.storedFields("message"); 
			GetResponse getResponse = client.get(request);
			String message = getResponse.getField("message").getValue();*/
			
			
			//3、发送请求		
			GetResponse getResponse = null;
			try {
				// 同步请求
			    getResponse = client.get(request);
			} catch (ElasticsearchException e) {
			    if (e.status() == RestStatus.NOT_FOUND) {
			    	logger.error("没有找到该id的文档" );
			    }
			    if (e.status() == RestStatus.CONFLICT) {
			    	logger.error("获取时版本冲突了，请在此写冲突处理逻辑！" );
			    }
			    logger.error("获取文档异常", e);
			}
			
			//4、处理响应
			if(getResponse != null) {
				String index = getResponse.getIndex();
				String type = getResponse.getType();
				String id = getResponse.getId();
				if (getResponse.isExists()) { // 文档存在
				    long version = getResponse.getVersion();
				    String sourceAsString = getResponse.getSourceAsString(); //结果取成 String       
				    Map<String, Object> sourceAsMap = getResponse.getSourceAsMap();  // 结果取成Map
				    byte[] sourceAsBytes = getResponse.getSourceAsBytes();    //结果取成字节数组
				    
				    logger.info("index:" + index + "  type:" + type + "  id:" + id);
				    logger.info(sourceAsString);
				    
				} else {
					logger.error("没有找到该id的文档" );
				}
			}
			
			
			//异步方式发送索引请求
			/*
			ActionListener<GetResponse> listener = new ActionListener<GetResponse>() {
			    @Override
			    public void onResponse(GetResponse getResponse) {
			        
			    }
			
			    @Override
			    public void onFailure(Exception e) {
			        
			    }
			};
			client.getAsync(request, listener);
			*/
			
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}
  • A granel
package com.dongnao.es_hrset_client;

import java.io.IOException;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.DocWriteRequest;
import org.elasticsearch.action.DocWriteResponse;
import org.elasticsearch.action.bulk.BulkItemResponse;
import org.elasticsearch.action.bulk.BulkRequest;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.update.UpdateResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;

public class BulkDemo {
	
	private static Logger logger = LogManager.getRootLogger();  

	public static void main(String[] args) {
		try (RestHighLevelClient client = InitDemo.getClient();) {
			
			// 1、创建批量操作请求
			BulkRequest request = new BulkRequest(); 
			request.add(new IndexRequest("mess", "_doc", "1")  
			        .source(XContentType.JSON,"field", "foo"));
			request.add(new IndexRequest("mess", "_doc", "2")  
			        .source(XContentType.JSON,"field", "bar"));
			request.add(new IndexRequest("mess", "_doc", "3")  
			        .source(XContentType.JSON,"field", "baz"));
			
			/*
			request.add(new DeleteRequest("mess", "_doc", "3")); 
			request.add(new UpdateRequest("mess", "_doc", "2") 
			        .doc(XContentType.JSON,"other", "test"));
			request.add(new IndexRequest("mess", "_doc", "4")  
			        .source(XContentType.JSON,"field", "baz"));
			*/
			
			// 2、可选的设置
			/*
			request.timeout("2m");
			request.setRefreshPolicy("wait_for");  
			request.waitForActiveShards(2);
			*/
			
			
			//3、发送请求		
		
			// 同步请求
			BulkResponse bulkResponse = client.bulk(request);
			
			
			//4、处理响应
			if(bulkResponse != null) {
				for (BulkItemResponse bulkItemResponse : bulkResponse) { 
				    DocWriteResponse itemResponse = bulkItemResponse.getResponse(); 

				    if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.INDEX
				            || bulkItemResponse.getOpType() == DocWriteRequest.OpType.CREATE) { 
				        IndexResponse indexResponse = (IndexResponse) itemResponse;
				        //TODO 新增成功的处理

				    } else if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.UPDATE) { 
				        UpdateResponse updateResponse = (UpdateResponse) itemResponse;
				       //TODO 修改成功的处理

				    } else if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.DELETE) { 
				        DeleteResponse deleteResponse = (DeleteResponse) itemResponse;
				        //TODO 删除成功的处理
				    }
				}
			}
			
			
			//异步方式发送批量操作请求
			/*
			ActionListener<BulkResponse> listener = new ActionListener<BulkResponse>() {
			    @Override
			    public void onResponse(BulkResponse bulkResponse) {
			        
			    }
			
			    @Override
			    public void onFailure(Exception e) {
			        
			    }
			};
			client.bulkAsync(request, listener);
			*/
			
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}
  • búsqueda
package com.dongnao.es_hrset_client;

import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.concurrent.TimeUnit;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.action.search.ShardSearchFailure;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.suggest.Suggest;
import org.elasticsearch.search.suggest.term.TermSuggestion;

public class SearchDemo {
	
	private static Logger logger = LogManager.getRootLogger();  

	public static void main(String[] args) {
		try (RestHighLevelClient client = InitDemo.getClient();) {
			
			// 1、创建search请求
			//SearchRequest searchRequest = new SearchRequest();
			SearchRequest searchRequest = new SearchRequest("bank"); 
			searchRequest.types("_doc");
			
			// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
			SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); 
			
			//构造QueryBuilder
			/*QueryBuilder matchQueryBuilder = QueryBuilders.matchQuery("user", "kimchy")
                    .fuzziness(Fuzziness.AUTO)
                    .prefixLength(3)
                    .maxExpansions(10);
			sourceBuilder.query(matchQueryBuilder);*/
			
			sourceBuilder.query(QueryBuilders.termQuery("age", 24)); 
			sourceBuilder.from(0); 
			sourceBuilder.size(10); 
			sourceBuilder.timeout(new TimeValue(60, TimeUnit.SECONDS)); 
			
			//是否返回_source字段
			//sourceBuilder.fetchSource(false);
			
			//设置返回哪些字段
			/*String[] includeFields = new String[] {"title", "user", "innerObject.*"};
			String[] excludeFields = new String[] {"_type"};
			sourceBuilder.fetchSource(includeFields, excludeFields);*/
			
			//指定排序
			//sourceBuilder.sort(new ScoreSortBuilder().order(SortOrder.DESC)); 
			//sourceBuilder.sort(new FieldSortBuilder("_uid").order(SortOrder.ASC));
			
			// 设置返回 profile 
			//sourceBuilder.profile(true);
			
			//将请求体加入到请求中
			searchRequest.source(sourceBuilder);
			
			// 可选的设置
			//searchRequest.routing("routing");
			
			// 高亮设置
			/*
			HighlightBuilder highlightBuilder = new HighlightBuilder(); 
			HighlightBuilder.Field highlightTitle =
			        new HighlightBuilder.Field("title"); 
			highlightTitle.highlighterType("unified");  
			highlightBuilder.field(highlightTitle);  
			HighlightBuilder.Field highlightUser = new HighlightBuilder.Field("user");
			highlightBuilder.field(highlightUser);
			sourceBuilder.highlighter(highlightBuilder);*/
			
			
			//加入聚合
			/*TermsAggregationBuilder aggregation = AggregationBuilders.terms("by_company")
			        .field("company.keyword");
			aggregation.subAggregation(AggregationBuilders.avg("average_age")
			        .field("age"));
			sourceBuilder.aggregation(aggregation);*/
			
			//做查询建议
			/*SuggestionBuilder termSuggestionBuilder =
				    SuggestBuilders.termSuggestion("user").text("kmichy"); 
				SuggestBuilder suggestBuilder = new SuggestBuilder();
				suggestBuilder.addSuggestion("suggest_user", termSuggestionBuilder); 
			sourceBuilder.suggest(suggestBuilder);*/
			
			//3、发送请求		
			SearchResponse searchResponse = client.search(searchRequest);
			
			
			//4、处理响应
			//搜索结果状态信息
			RestStatus status = searchResponse.status();
			TimeValue took = searchResponse.getTook();
			Boolean terminatedEarly = searchResponse.isTerminatedEarly();
			boolean timedOut = searchResponse.isTimedOut();
			
			//分片搜索情况
			int totalShards = searchResponse.getTotalShards();
			int successfulShards = searchResponse.getSuccessfulShards();
			int failedShards = searchResponse.getFailedShards();
			for (ShardSearchFailure failure : searchResponse.getShardFailures()) {
			    // failures should be handled here
			}
			
			//处理搜索命中文档结果
			SearchHits hits = searchResponse.getHits();
			
			long totalHits = hits.getTotalHits();
			float maxScore = hits.getMaxScore();
			
			SearchHit[] searchHits = hits.getHits();
			for (SearchHit hit : searchHits) {
			    // do something with the SearchHit
				
				String index = hit.getIndex();
				String type = hit.getType();
				String id = hit.getId();
				float score = hit.getScore();
				
				//取_source字段值
				String sourceAsString = hit.getSourceAsString(); //取成json串
				Map<String, Object> sourceAsMap = hit.getSourceAsMap(); // 取成map对象
				//从map中取字段值
				/*
				String documentTitle = (String) sourceAsMap.get("title"); 
				List<Object> users = (List<Object>) sourceAsMap.get("user");
				Map<String, Object> innerObject = (Map<String, Object>) sourceAsMap.get("innerObject");
				*/
				logger.info("index:" + index + "  type:" + type + "  id:" + id);
			    logger.info(sourceAsString);
			    
				//取高亮结果
				/*Map<String, HighlightField> highlightFields = hit.getHighlightFields();
			    HighlightField highlight = highlightFields.get("title"); 
			    Text[] fragments = highlight.fragments();  
			    String fragmentString = fragments[0].string();*/
			}
			
			// 获取聚合结果
			/*
			Aggregations aggregations = searchResponse.getAggregations();
			Terms byCompanyAggregation = aggregations.get("by_company"); 
			Bucket elasticBucket = byCompanyAggregation.getBucketByKey("Elastic"); 
			Avg averageAge = elasticBucket.getAggregations().get("average_age"); 
			double avg = averageAge.getValue();
			*/
			
			// 获取建议结果
			/*Suggest suggest = searchResponse.getSuggest(); 
			TermSuggestion termSuggestion = suggest.getSuggestion("suggest_user"); 
			for (TermSuggestion.Entry entry : termSuggestion.getEntries()) { 
			    for (TermSuggestion.Entry.Option option : entry) { 
			        String suggestText = option.getText().string();
			    }
			}
			*/
			
			//异步方式发送获查询请求
			/*
			ActionListener<SearchResponse> listener = new ActionListener<SearchResponse>() {
			    @Override
			    public void onResponse(SearchResponse getResponse) {
			        //结果获取
			    }
			
			    @Override
			    public void onFailure(Exception e) {
			        //失败处理
			    }
			};
			client.searchAsync(searchRequest, listener); 
			*/
			
		} catch (IOException e) {
			logger.error(e);
		}
	}
}
  • destacar
package com.dongnao.es_hrset_client;

import java.io.IOException;
import java.util.Map;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.text.Text;
import org.elasticsearch.index.query.QueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;

public class HighlightDemo {
	
	private static Logger logger = LogManager.getRootLogger();  

	public static void main(String[] args) {
		try (RestHighLevelClient client = InitDemo.getClient();) {
			
			// 1、创建search请求
			SearchRequest searchRequest = new SearchRequest("hl_test"); 
			
			// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
			SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); 
			
			//构造QueryBuilder
			QueryBuilder matchQueryBuilder = QueryBuilders.matchQuery("title", "lucene solr");
			sourceBuilder.query(matchQueryBuilder);
			
			//分页设置
			/*sourceBuilder.from(0); 
			sourceBuilder.size(5); ;*/ 
			
					
			// 高亮设置
			HighlightBuilder highlightBuilder = new HighlightBuilder(); 
			highlightBuilder.requireFieldMatch(false).field("title").field("content")
				.preTags("<strong>").postTags("</strong>");
			//不同字段可有不同设置，如不同标签
			/*HighlightBuilder.Field highlightTitle = new HighlightBuilder.Field("title"); 
			highlightTitle.preTags("<strong>").postTags("</strong>");
			highlightBuilder.field(highlightTitle);  
			HighlightBuilder.Field highlightContent = new HighlightBuilder.Field("content");
			highlightContent.preTags("<b>").postTags("</b>");
			highlightBuilder.field(highlightContent).requireFieldMatch(false);*/
			
			sourceBuilder.highlighter(highlightBuilder);
			
			searchRequest.source(sourceBuilder);
			
			//3、发送请求		
			SearchResponse searchResponse = client.search(searchRequest);
			
			
			//4、处理响应
			if(RestStatus.OK.equals(searchResponse.status())) {
				//处理搜索命中文档结果
				SearchHits hits = searchResponse.getHits();
				long totalHits = hits.getTotalHits();
				
				SearchHit[] searchHits = hits.getHits();
				for (SearchHit hit : searchHits) {		
					String index = hit.getIndex();
					String type = hit.getType();
					String id = hit.getId();
					float score = hit.getScore();
					
					//取_source字段值
					//String sourceAsString = hit.getSourceAsString(); //取成json串
					Map<String, Object> sourceAsMap = hit.getSourceAsMap(); // 取成map对象
					//从map中取字段值
					/*String title = (String) sourceAsMap.get("title"); 
					String content  = (String) sourceAsMap.get("content"); */
					logger.info("index:" + index + "  type:" + type + "  id:" + id);
				    logger.info("sourceMap : " +  sourceAsMap);
					//取高亮结果
					Map<String, HighlightField> highlightFields = hit.getHighlightFields();
				    HighlightField highlight = highlightFields.get("title"); 
				    if(highlight != null) {
					    Text[] fragments = highlight.fragments();  //多值的字段会有多个值
					    if(fragments != null) {
					    	String fragmentString = fragments[0].string();
					    	logger.info("title highlight : " +  fragmentString);
					    	//可用高亮字符串替换上面sourceAsMap中的对应字段返回到上一级调用
					    	//sourceAsMap.put("title", fragmentString);
					    }
				    }
				    
				    highlight = highlightFields.get("content"); 
				    if(highlight != null) {
					    Text[] fragments = highlight.fragments();  //多值的字段会有多个值
					    if(fragments != null) {
					    	String fragmentString = fragments[0].string();
					    	logger.info("content highlight : " +  fragmentString);
					    	//可用高亮字符串替换上面sourceAsMap中的对应字段返回到上一级调用
					    	//sourceAsMap.put("content", fragmentString);
					    }
				    }
				}
			}
			
		} catch (IOException e) {
			logger.error(e);
		}
	}
}
  • sugerir
package com.dongnao.es_hrset_client;

import java.io.IOException;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.suggest.Suggest;
import org.elasticsearch.search.suggest.SuggestBuilder;
import org.elasticsearch.search.suggest.SuggestBuilders;
import org.elasticsearch.search.suggest.SuggestionBuilder;
import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
import org.elasticsearch.search.suggest.term.TermSuggestion;

public class SuggestDemo {
	
	private static Logger logger = LogManager.getRootLogger();  
	
	public static void termSuggest() {
		try (RestHighLevelClient client = InitDemo.getClient();) {
			
			// 1、创建search请求
			//SearchRequest searchRequest = new SearchRequest();
			SearchRequest searchRequest = new SearchRequest("mess"); 
			
			// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
			SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); 
			 
			sourceBuilder.size(0); 
			
			//做查询建议		
			//词项建议
			SuggestionBuilder termSuggestionBuilder =
				    SuggestBuilders.termSuggestion("user").text("kmichy"); 
			SuggestBuilder suggestBuilder = new SuggestBuilder();
			suggestBuilder.addSuggestion("suggest_user", termSuggestionBuilder); 	
			sourceBuilder.suggest(suggestBuilder);
			
			searchRequest.source(sourceBuilder);	
			
			//3、发送请求		
			SearchResponse searchResponse = client.search(searchRequest);
			
			
			//4、处理响应
			//搜索结果状态信息
			if(RestStatus.OK.equals(searchResponse.status())) {
				// 获取建议结果
				Suggest suggest = searchResponse.getSuggest(); 
				TermSuggestion termSuggestion = suggest.getSuggestion("suggest_user"); 
				for (TermSuggestion.Entry entry : termSuggestion.getEntries()) { 
					logger.info("text: " + entry.getText().string());
				    for (TermSuggestion.Entry.Option option : entry) { 
				        String suggestText = option.getText().string();
				        logger.info("   suggest option : " + suggestText);
				    }
				}
			}
			/*
			  "suggest": {
			    "my-suggestion": [
			      {
			        "text": "tring",
			        "offset": 0,
			        "length": 5,
			        "options": [
			          {
			            "text": "trying",
			            "score": 0.8,
			            "freq": 1
			          }
			        ]
			      },
			      {
			        "text": "out",
			        "offset": 6,
			        "length": 3,
			        "options": []
			      },
			      {
			        "text": "elasticsearch",
			        "offset": 10,
			        "length": 13,
			        "options": []
			      }
			    ]
			  }*/

		} catch (IOException e) {
			logger.error(e);
		}
	}
	
	public static void completionSuggester() {
		try (RestHighLevelClient client = InitDemo.getClient();) {
			
			// 1、创建search请求
			//SearchRequest searchRequest = new SearchRequest();
			SearchRequest searchRequest = new SearchRequest("music"); 
			
			// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
			SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); 
			 
			sourceBuilder.size(0); 
			
			//做查询建议		
			//自动补全
			/*POST music/_search?pretty
					{
					    "suggest": {
					        "song-suggest" : {
					            "prefix" : "lucene s", 
					            "completion" : { 
					                "field" : "suggest" ,
					                "skip_duplicates": true
					            }
					        }
					    }
					}*/

			SuggestionBuilder termSuggestionBuilder =
				    SuggestBuilders.completionSuggestion("suggest").prefix("lucene s")
				    .skipDuplicates(true); 
			SuggestBuilder suggestBuilder = new SuggestBuilder();
			suggestBuilder.addSuggestion("song-suggest", termSuggestionBuilder); 	
			sourceBuilder.suggest(suggestBuilder);
			
			searchRequest.source(sourceBuilder);	
			
			//3、发送请求		
			SearchResponse searchResponse = client.search(searchRequest);
			
			
			//4、处理响应
			//搜索结果状态信息
			if(RestStatus.OK.equals(searchResponse.status())) {
				// 获取建议结果
				Suggest suggest = searchResponse.getSuggest(); 
				CompletionSuggestion termSuggestion = suggest.getSuggestion("song-suggest"); 
				for (CompletionSuggestion.Entry entry : termSuggestion.getEntries()) { 
					logger.info("text: " + entry.getText().string());
				    for (CompletionSuggestion.Entry.Option option : entry) { 
				        String suggestText = option.getText().string();
				        logger.info("   suggest option : " + suggestText);
				    }
				}
			}

		} catch (IOException e) {
			logger.error(e);
		}
	}

	public static void main(String[] args) {
		termSuggest();
		
		logger.info("--------------------------------------");
		
		completionSuggester();
	}
}
  • agregación
package com.dongnao.es_hrset_client;

import java.io.IOException;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.Aggregations;
import org.elasticsearch.search.aggregations.BucketOrder;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.aggregations.bucket.terms.Terms.Bucket;
import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
import org.elasticsearch.search.aggregations.metrics.avg.Avg;
import org.elasticsearch.search.builder.SearchSourceBuilder;

public class AggregationDemo {
	
	private static Logger logger = LogManager.getRootLogger();  

	public static void main(String[] args) {
		try (RestHighLevelClient client = InitDemo.getClient();) {
			
			// 1、创建search请求
			//SearchRequest searchRequest = new SearchRequest();
			SearchRequest searchRequest = new SearchRequest("bank"); 
			
			// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
			SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); 
			 
			sourceBuilder.size(0); 

			//加入聚合
			//字段值项分组聚合
			TermsAggregationBuilder aggregation = AggregationBuilders.terms("by_age")
			        .field("age").order(BucketOrder.aggregation("average_balance", true));
			//计算每组的平均balance指标
			aggregation.subAggregation(AggregationBuilders.avg("average_balance")
			        .field("balance"));
			sourceBuilder.aggregation(aggregation);
			
			searchRequest.source(sourceBuilder);
			
			//3、发送请求		
			SearchResponse searchResponse = client.search(searchRequest);
				
			//4、处理响应
			//搜索结果状态信息
			if(RestStatus.OK.equals(searchResponse.status())) {
				// 获取聚合结果
				Aggregations aggregations = searchResponse.getAggregations();
				Terms byAgeAggregation = aggregations.get("by_age"); 
				logger.info("aggregation by_age 结果");
				logger.info("docCountError: " + byAgeAggregation.getDocCountError());
				logger.info("sumOfOtherDocCounts: " + byAgeAggregation.getSumOfOtherDocCounts());
				logger.info("------------------------------------");
				for(Bucket buck : byAgeAggregation.getBuckets()) {
					logger.info("key: " + buck.getKeyAsNumber());
					logger.info("docCount: " + buck.getDocCount());
					logger.info("docCountError: " + buck.getDocCountError());
					//取子聚合
					Avg averageBalance = buck.getAggregations().get("average_balance"); 

					logger.info("average_balance: " + averageBalance.getValue());
					logger.info("------------------------------------");
				}
				//直接用key 来去分组
				/*Bucket elasticBucket = byCompanyAggregation.getBucketByKey("24"); 
				Avg averageAge = elasticBucket.getAggregations().get("average_age"); 
				double avg = averageAge.getValue();*/
				
			}
			
		} catch (IOException e) {
			logger.error(e);
		}
	}
}

QueryBuilder correspondiente a varias consultas

https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high-query-builders.html

AggregationBuilder correspondiente a varias agregaciones

https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high-aggregation-builders.html

Cliente Java

Descripción del cliente Java

  •   El cliente Java usa TransportClient, y varias operaciones son esencialmente asincrónicas (puede usar el escucha o devolver Future).
  •   Nota: En el plan de desarrollo de ES, TransportClient se eliminará a partir de la versión 7.0, y TransportClient se eliminará por completo en la versión 8.0 y se reemplazará por High Level REST Client.
  •   La API de operación en el cliente REST de alto nivel y el cliente java son casi iguales.

Enlace de aprendizaje oficial

https://www.elastic.co/guide/en/elasticsearch/client/java-api/current/index.html

Nota de compatibilidad

  • Utilice la versión del cliente que sea coherente con la versión del servidor ES

Integración maven del cliente Java

<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>transport</artifactId>
    <version>6.2.4</version>
</dependency>

Los otros frascos que dependen son básicamente los mismos que el cliente REST alto

Descripción del registrador del cliente Java

Se utiliza el componente de registro log4j2. Si desea utilizar otros componentes de registro, puede utilizar slf4j como puente

Cliente inicial

// on startup
Settings settings = Settings.builder()   //连接集群的设置
        .put("cluster.name", "myClusterName").build();
TransportClient client = new PreBuiltTransportClient(settings)
        .addTransportAddress(new TransportAddress(InetAddress.getByName("host1"), 9300))
        .addTransportAddress(new TransportAddress(InetAddress.getByName("host2"), 9300));//连接的transport地址，注意端口是9300


// on shutdown
//在关闭时记得关闭客户端对象
client.close();

Configuración inicial del cliente Descripción del parámetro disponible

  • cluster.name         especifica el nombre del clúster. Si el nombre del clúster no es el elasticsearch predeterminado, debe especificarlo.
  • Si client.transport.sniff se         establece en true, todo el clúster se rastreará automáticamente y los nodos del clúster se agregarán automáticamente a la lista de conexiones.
  • client.transport.ignore_cluster_name Se         establece en true para ignorar la validación del nombre del clúster de los nodos conectados. (desde 0.19.4)
  • client.transport.ping_timeout         El tiempo para esperar una respuesta de ping de un nodo. El valor predeterminado es 5 segundos.
  • client.transport.nodes_sampler_interval Frecuencia         de muestreo / ping de los nodos enumerados y conectados. El valor predeterminado es 5 segundos.

API de documentos API de manipulación de documentos

Enlace de introducción detallada en el sitio web oficial: https://www.elastic.co/guide/en/elasticsearch/client/java-api/6.2/java-docs.html

API de búsqueda

https://www.elastic.co/guide/en/elasticsearch/client/java-api/6.2/java-search.html

Ejemplo de código: dirección es-java-client

http://code.dongnaoedu.com/3266399810/vip-elasticsearch/tree/master/

Enlace de aprendizaje Spring Data Elasticsearch

https://docs.spring.io/spring-data/elasticsearch/docs/current/reference/html/ https://github.com/spring-projects/spring-data-elasticsearch.

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Origin blog.csdn.net/qq_34050399/article/details/113247498
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