Doc地址：https://www.elastic.co/guide/en/elasticsearch/client/java-rest/7.10/index.html

1.pom.xml

<dependency>
    <groupId>org.elasticsearch</groupId>
    <artifactId>elasticsearch</artifactId>
    <version>7.10.2</version>
</dependency>

		
<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-high-level-client</artifactId>
    <version>7.10.2</version>
</dependency>

2.Test.java

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.List;
import java.util.Objects;

import org.apache.http.Header;
import org.apache.http.HttpHost;
import org.apache.http.impl.nio.client.CloseableHttpAsyncClient;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.Node;
import org.elasticsearch.client.NodeSelector;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestClientBuilder;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.core.GetSourceRequest;
import org.elasticsearch.client.core.GetSourceResponse;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentFactory;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.sort.ScoreSortBuilder;
import org.elasticsearch.search.sort.SortOrder;

public class Test {
	
	

	public static void main(String[] args) throws IOException {
		ArrayList<HttpHost> hostList = new ArrayList<>();
		
		List<Node> nodes = new ArrayList<>();
		
		hostList.add(new HttpHost("127.0.0.1", 9200, "http"));
		RestHighLevelClient client = new RestHighLevelClient(
		        RestClient.builder(hostList.get(0)));
		
		XContentBuilder builder = XContentFactory.jsonBuilder();
		builder.startObject();
		{
		    builder.field("title", "test");
		    builder.timeField("date", new Date());
		    builder.field("content","Biden didn't mention his predecessor by name, "
		    		+ "but especially in the early moments of his speech, "
		    		+ "it was very clear that the current President lays much of the blame for "
		    		+ "the country's struggles with the coronavirus "
		    		+ "pandemic at the feet of the last President."
		    		+ "A year ago, we were hit with a virus that was met with silence and spread unchecked, "
		    		+ "denials for days, weeks, then months, "
		    		+ "Biden said at one point. "
		    		+ "That led to more deaths, more infections, more stress and more loneliness."
		    		+ "At another point, Biden pulled out his mask "
		    		+ "and expressed amazement that it had been turned into some sort of political statement.") ; 
		    			}
		builder.endObject();
		IndexRequest request = new IndexRequest("cn-news")
		    .id("3").source(builder);
		/*IndexResponse response = client.index(request, RequestOptions.DEFAULT);
		System.out.println(response);
		client.close();*/
		searchSourceWithFulltextMatch(client);
	}
	
	/**
	 * @Title: searchSourceWithDocId   
	 * @Description: 通过DocId查询       
	 * @author: 徐蜀黍
	 * @date: 2021年3月12日 下午4:03:20    
	 * @param client
	 */
	public static void searchSourceWithDocId(RestHighLevelClient client) {
		try {
			GetSourceRequest getSourceRequest = new GetSourceRequest("cn-news", "1");
			GetSourceResponse response = client.getSource(getSourceRequest, RequestOptions.DEFAULT);
			System.out.println(response);
		} catch (IOException e) {
			e.printStackTrace();
		}finally {
			try {
				client.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
	
	/**
	 * @Title: searchAllSourceWithIndexs   
	 * @Description:查询指定index的全部数据
	 * @author: 徐蜀黍
	 * @date: 2021年3月12日 下午4:03:46    
	 * @param client
	 */
	public static void searchAllSourceWithIndexs(RestHighLevelClient client) {
		try {
			SearchRequest searchRequest = new SearchRequest("cn-news"); 
			SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder(); 
			searchSourceBuilder.query(QueryBuilders.matchAllQuery()); 
			searchRequest.source(searchSourceBuilder); 
			SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
			System.out.println(response);
		} catch (IOException e) {
			e.printStackTrace();
		}finally {
			try {
				client.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
	
	/**
	 * @Title: searchSourceWithCondition   
	 * @Description:按条件分页查询
	 * @author: 徐蜀黍
	 * @date: 2021年3月12日 下午4:04:36    
	 * @param client
	 * @param condition
	 */
	public static void searchSourceWithCondition(RestHighLevelClient client, String condition) {
		try {
			SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
			sourceBuilder.query(Objects.isNull(condition) ? QueryBuilders.matchAllQuery()
					: QueryBuilders.queryStringQuery(condition));
			sourceBuilder.from(0);
			sourceBuilder.size(10);
			sourceBuilder.timeout();
			SearchRequest searchRequest = new SearchRequest();
			searchRequest.indices("cn-news");
			searchRequest.source(sourceBuilder);

			SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
			System.out.println(response);
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				client.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}

	/**
	 * @Title: searchSourceWithFulltextMatch   
	 * @Description:全文检索         
	 * @author: 徐蜀黍
	 * @date: 2021年3月12日 下午4:42:58    
	 * @param client
	 */
	public static void searchSourceWithFulltextMatch(RestHighLevelClient client) {
		try {
			SearchRequest searchRequest = new SearchRequest("cn-news");
			SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();

			// 设置高亮HighlightBuilder
			HighlightBuilder highlightBuilder = new HighlightBuilder();
			HighlightBuilder.Field highlightTitle = new HighlightBuilder.Field("title");
			HighlightBuilder.Field highlightContent = new HighlightBuilder.Field("content");
			highlightTitle.highlighterType("unified");
			highlightBuilder.field(highlightTitle);
			highlightBuilder.field(highlightContent);
			
			// 设置查询QueryBuilders
			searchSourceBuilder.query(QueryBuilders.multiMatchQuery("test", "title", "content"))
					.sort(new ScoreSortBuilder().order(SortOrder.DESC))
					.highlighter(highlightBuilder)
					.from(0)
					.size(10);
			searchRequest.source(searchSourceBuilder);
			
			SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
			System.out.println(response);
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				client.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
}