Elasticsearch学习笔记之（七）Elasticsearch Java client

目录

ES Client 简介

ES是一个服务，采用C/S结构

回顾 ES的架构

ES支持的客户端连接方式

ES提供了多种编程语言客户端

Java REST Client

ES提供了两个JAVA REST client 版本

Java Low Level REST Client 说明

Java High Level REST Client 说明

兼容性说明

Java High Level REST Client  maven 集成

Java High Level REST Client  初始化

API

各种查询对应的QueryBuilder

各种聚合对应的AggregationBuilder

Java Client

Java Client 说明

官方学习链接

兼容性说明

Java Client  maven 集成

Java Client  logger 日志器说明

Init Client

Init Client setting 可用参数说明

Document API 文档操作API

Search API

代码示例： es-java-client  地址

Spring Data Elasticsearch 学习链接

---

ES Client 简介

ES是一个服务，采用C/S结构

回顾 ES的架构

ES支持的客户端连接方式

•  REST API ，端口 9200  
• Transport 连接    端口 9300

ES提供了多种编程语言客户端

Client api 学习链接 https://www.elastic.co/guide/en/elasticsearch/client/index.html

Java REST Client

ES提供了两个JAVA REST client 版本

•   Java Low Level REST Client: 低级别的REST客户端，通过http与集群交互，用户需自己编组请求JSON串，及解析响应JSON串。兼容所有ES版本。
•   Java High Level REST Client: 高级别的REST客户端，基于低级别的REST客户端，增加了编组请求、解析响应等相关api。

Java Low Level REST Client 说明

•  特点，maven 引入、使用介绍请参阅：

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

•  API doc 请参阅：

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

Java High Level REST Client 说明

•   从6.0.0开始加入的，目的是以java面向对象的方式来进行请求、响应处理。
•   每个API 支持 同步/异步 两种方式，同步方法直接返回一个结果对象。异步的方法以 async 为后缀，通过listener 参数来通知结果。
•   高级java REST 客户端依赖Elasticsearch core project

兼容性说明

•   依赖 java1.8  和 Elasticsearch core project
•   请使用与服务端ES版本一致的客户端版本

Java High Level REST Client  maven 集成

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

Java High Level REST Client  初始化

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

给定集群的多个节点地址，将客户端负载均衡地向这个节点地址集发请求

Client 不再使用了，记得关闭它。

client.close();

API

API及用法示例，请参考：

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

• Create index

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();
		}
	}
}

• index  document

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();
		}
	}
}

• get  document

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();
		}
	}
}

• Bulk

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();
		}
	}
}

• search

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);
		}
	}
}

• highlight

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);
		}
	}
}

• suggest

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();
	}
}

• aggregation

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);
		}
	}
}

各种查询对应的QueryBuilder

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

各种聚合对应的AggregationBuilder

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

Java Client

Java Client 说明

•   java client 使用 TransportClient，各种操作本质上都是异步的(可以用 listener，或返回 Future ）。
•   注意：ES的发展规划中在7.0版本开始将废弃 TransportClient，8.0版本中将完全移除 TransportClient，取而代之的是High Level REST Client。
•   High Level REST Client 中的操作API和java client 大多是一样的。

官方学习链接

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

兼容性说明

• 请使用与服务端ES版本一致的客户端版本

Java Client  maven 集成

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

依赖的其他jar和high REST Client基本一样

Java Client  logger 日志器说明

使用的是 log4j2 日志组件。 如果要使用其他的日志组件，可使用slf4j作桥

Init Client

// 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();

Init Client setting 可用参数说明

• cluster.name         指定集群的名字，如果集群的名字不是默认的elasticsearch，需指定。
• client.transport.sniff         设置为true,将自动嗅探整个集群，自动加入集群的节点到连接列表中。
• client.transport.ignore_cluster_name         Set to true to ignore cluster name validation of connected nodes. (since 0.19.4)
• client.transport.ping_timeout         The time to wait for a ping response from a node. Defaults to 5s.
• client.transport.nodes_sampler_interval         How often to sample / ping the nodes listed and connected. Defaults to 5s.

Document API 文档操作API

官网详细介绍链接： https://www.elastic.co/guide/en/elasticsearch/client/java-api/6.2/java-docs.html

Search API

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

代码示例： es-java-client  地址

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

Spring Data Elasticsearch 学习链接

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