Elasticsearch(五):JAVA客户端操作Elasticsearch

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/a913858/article/details/86760954

前面的章节使用curl的方式去添加修改我们的es数据，然后来看看Java后台是怎么来操作es数据。
一、环境准备
没有环境的朋友，请先参考前面提到的安装方式进行安装。如果有安装不成功者，可以联系我。
文章最后我会把个人微信提供下，欢迎跟各位Java友友一起交流成长。

1. es服务端
2. es-head(用来辅助es服务端)
3. ik中文分词器
4. eclipse
5. maven

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.guo.elasticsearch</groupId>
  <artifactId>ElasticsearchHandler</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>ElasticsearchHandler Maven Webapp</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    
    <dependency>  
		    <groupId>org.elasticsearch</groupId>  
		    <artifactId>elasticsearch</artifactId>  
		    <version>6.1.1</version>  
		 </dependency>  
		<dependency>
	    <groupId>org.elasticsearch.client</groupId>
	    	<artifactId>transport</artifactId>
	    <version>6.1.1</version>
		</dependency>
		<dependency>
			<groupId>org.apache.logging.log4j</groupId>
			<artifactId>log4j-core</artifactId>
			<version>2.9.1</version>
		</dependency>
		<dependency>
		  <groupId>org.apache.logging.log4j</groupId>
		  <artifactId>log4j-api</artifactId>
		  <version>2.9.1</version>
		</dependency>
		<dependency>
			<groupId>org.slf4j</groupId>
			<artifactId>slf4j-api</artifactId>
			<version>1.7.21</version>
		</dependency>
    
  </dependencies>
  <build>
    <finalName>ElasticsearchHandler</finalName>
  </build>
</project>

有的朋友习惯idea也可以用这个，相信Java友友这个应该都比较熟悉的，我创建的是maven项目，所以也需要maven插件的。也可以不用maven，那就需要自己去找jar包了。这些相信有基础的Java友友一般都会，就不一一介绍了。

二、代码准备

1.实体类

package com.es;

/**
 * 
* 功能描述: 实体类
* @author gqh  
* @date 2019年2月3日
 */
public class KnowledgeVO {
	
	private String id;
	private String title;
	private String keyword;
	private String source;
	private String version;
	private String content;
	private String creatorName;
	private String createTime;
	private String indexId;
	
	public String getId() {
		return id;
	}
	public void setId(String id) {
		this.id = id;
	}
	public String getTitle() {
		return title;
	}
	public void setTitle(String title) {
		this.title = title;
	}
	public String getKeyword() {
		return keyword;
	}
	public void setKeyword(String keyword) {
		this.keyword = keyword;
	}
	public String getSource() {
		return source;
	}
	public void setSource(String source) {
		this.source = source;
	}
	public String getVersion() {
		return version;
	}
	public void setVersion(String version) {
		this.version = version;
	}
	public String getContent() {
		return content;
	}
	public void setContent(String content) {
		this.content = content;
	}
	public String getCreatorName() {
		return creatorName;
	}
	public void setCreatorName(String creatorName) {
		this.creatorName = creatorName;
	}
	public String getCreateTime() {
		return createTime;
	}
	public void setCreateTime(String createTime) {
		this.createTime = createTime;
	}
	public String getIndexId() {
		return indexId;
	}
	public void setIndexId(String indexId) {
		this.indexId = indexId;
	}

}

简单的弄了一个实体类。

2.转换es–json工具类

package com.es;

import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentFactory;


/** 
* 功能描述:用于对象转换json
* @author gqh  
* @date 2019年2月3日  
*/
public class JsonUtil {
	
	public static String objJsonDate(KnowledgeVO vo) {
		String jsonData = null;
		try {
			//使用XContentBuilder创建json数据
			XContentBuilder jsonBuilder = XContentFactory.jsonBuilder();
			jsonBuilder.startObject()
			.field("id", vo.getId())
			.field("title", vo.getTitle())
			.field("keyword", vo.getKeyword())
			.field("source", vo.getSource())
			.field("version", vo.getVersion())
			.field("content", vo.getContent())
			.field("creatorName",vo.getCreatorName())
			.field("createTime",vo.getCreateTime())
			.endObject();
			jsonData = jsonBuilder.string();
			
		} catch (Exception e) {
			e.printStackTrace();
		}
		
		return jsonData;
	}
	
}

3.客户端连接

/**
	 * 
	 * 功能描述:创建客户端连接ES服务
	 * @return
	 */
	public static TransportClient getClient() {
		try {
			String ipAddress = "192.168.1.120";
			int port = 9300;
			//程序中更改集群结点名称 并且设置client.transport.sniff为true来使客户端去嗅探整个集群的状态
			Settings settings = Settings.builder()
					.put("client.transport.sniff",true)
					.build();
			client = new PreBuiltTransportClient(settings);
			client.addTransportAddress(new TransportAddress(InetAddress.getByName(ipAddress), port));
		} catch (UnknownHostException e) {
			e.printStackTrace();
		}
		
		return client;
	}

没有用到集群方式，但是我把集群的方式也加入了。
4.基本属性

	private static TransportClient client = null;
	
	private static String indexName = "knowledge";
	
	private static String indexType = "knowledge";
	
	private static Logger logger = LoggerFactory.getLogger(ElasticSearchHandler.class);

5.添加索引

/**
	 * 
	 * 功能描述:添加索引数据
	 * @param vo
	 * @return
	 */
	public synchronized static String createIndex(KnowledgeVO vo) {
		String doc_id = "";
		try {
			String jsonDate = JsonUtil.objJsonDate(vo);
			IndexRequestBuilder requestBuilder = getClient().prepareIndex(indexName,indexType);
			IndexResponse ir = requestBuilder.setSource(jsonDate,XContentType.JSON).execute().actionGet();
			String index_type = ir.getType();
			String index_name = ir.getIndex();
			long version = ir.getVersion();
			doc_id = ir.getId();
			logger.info("索引名:"+index_name);
			logger.info("索引类型:"+index_type);
			logger.info("索引版本号:"+version);
			logger.info("doc_id:"+doc_id);
		} catch (Exception e) {
			e.printStackTrace();
			logger.info("哇哦，添加索引失败了");
		}
		
		return doc_id;
		
	}

6.更新索引

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/**
	 * 功能描述:更新索引
	 */
	public static void updateIndex(KnowledgeVO vo) {
		try {
			UpdateRequest uRequest = new UpdateRequest();
			uRequest.index(indexName);
			uRequest.type(indexType);
			uRequest.id(vo.getIndexId());
			uRequest.doc("{\"title\":\"测试数据\"}", XContentType.JSON);
			getClient().update(uRequest).get();
		} catch (Exception e) {
			e.printStackTrace();
			logger.info("哇哦，更新索引失败了");
		}
	}

7.查询

/**
	 * 功能描述:查询
	 * @return
	 */
	public static List searcher(Map<String,String> pmap,int from, int size ) {
		List<KnowledgeVO> list = new ArrayList<KnowledgeVO>();
		BoolQueryBuilder queryBuilder = new BoolQueryBuilder();
		String searchWord = pmap.get("searchWord");
		queryBuilder
		.should(QueryBuilders.wildcardQuery("title", "*"+searchWord+"*"))
		.should(QueryBuilders.queryStringQuery("content:"+searchWord).defaultOperator(Operator.OR))
		.should(QueryBuilders.queryStringQuery("fileContent:"+searchWord).defaultOperator(Operator.OR))
		.should(QueryBuilders.queryStringQuery("keyword:"+searchWord).defaultOperator(Operator.OR));
		queryBuilder.minimumShouldMatch(1);
		SearchResponse searchResponse = getClient().prepareSearch(indexName).setTypes(indexType)
	        .setQuery(queryBuilder).setFrom(from).setSize(size)
	        .setExplain(true)
	        .execute()
	        .actionGet();
		SearchHits hits = searchResponse.getHits();
		long totalHits = hits.getTotalHits();
		logger.info("查询到记录数=" + totalHits);
		SearchHit[] searchHists = hits.getHits();
		if(searchHists.length > 0) {
			for(SearchHit hit:searchHists){
				logger.debug("hit.getId() =" + hit.getId());
				String id = (String)hit.getSourceAsMap().get("id");
				String title =  (String) hit.getSourceAsMap().get("title");
				String keyword = (String)hit.getSourceAsMap().get("keyword");
                String source =  (String) hit.getSourceAsMap().get("source");
                String version =  (String) hit.getSourceAsMap().get("version");
                String contents = (String) hit.getSourceAsMap().get("content");
                KnowledgeVO vo = new KnowledgeVO();
                vo.setId(id);
                vo.setTitle(title);
                vo.setKeyword(keyword);
                vo.setSource(source);
                vo.setVersion(version);
                vo.setContent(contents);
                list.add(vo);
			}
		}
		
		return list;
		
	}

我把返回的数据都加入list当中，后续有做web的时候，可以用来做展示。titile查询我加入一个类似于sql里面like查询的功能，区别于其他的普通查询。还有一些特殊的查询没有一一罗列，友友们可以自行学习。

8.删除索引

/**
	 * 功能描述:删除索引
	 * @param knowId
	 */
	public static void DelIndex(String id) {
		try {
			QueryBuilder queryBuilder = QueryBuilders.termQuery("id", id);
			DeleteByQueryAction.INSTANCE.newRequestBuilder(getClient())
				.filter(queryBuilder)
				.source(indexName)
				.get();
		} catch (Exception e) {
			e.printStackTrace();
			logger.info("哇哦，删除索引失败了");
		}
		
	}

9.测试类

public static void main(String[] args){
    	try{
    		//elasticsearch6.1.1版本测试
    		/*
    		添加方法
    		KnowledgeVO vo = new KnowledgeVO();
    		vo.setId("1234567");
    		vo.setTitle("软件大集合");
    		vo.setKeyword("Java");
    		vo.setSource("Oracle");
    		vo.setContent("Java数据");
    		vo.setVersion("1.0");
    		vo.setCreatorName("某某某");
    		vo.setIndexId("AWizBU0ygy2IhqmdsetP");
    		String indexId = createIndex(vo);
    		System.out.println("文档id===="+indexId);*/
    		
    		/*
    		 更新方法(记得放入索引id)
    		 String indexId = "AWizBU0ygy2IhqmdsetP";
    		 updateIndex(vo);
    		 */
    		
    		/*
    		查询方法
    		Map<String,String> param = new HashMap<String, String>();
    		param.put("searchWord", "王者");
    		List<KnowledgeVO> searcher = searcher(param,0,10);
    		for(int i=0;i<searcher.size();i++) {
    			String id = searcher.get(i).getId();
    			String title = searcher.get(i).getTitle();
    			String keyword = searcher.get(i).getKeyword();
    			String source = searcher.get(i).getSource();
    			System.out.println("id:"+id+"\ntitle:"+title+"\nkeyword:"+keyword+"\nsource:"+source);
    		}*/
    		//删除方法
    		DelIndex("123456");
    	}
    	catch(Exception e){
    		e.printStackTrace();
    	}
    }

Java友友可以自行去扩展每个方法根据自己需要的结果去处理。

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