1、api种类
1.1TransportClient
是Elasticsearch官方的api
TransportClient可以支持2.x，5.x版本，TransportClient将会在Elasticsearch 7.0弃用并在8.0中完成删除。
1.2RestClient
也是Elasticsearch官方的api。
官方地址：https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/index.html
替代TransportClient，它使用HTTP请求而不是Java序列化请求。
1.3Jest
Jest是Java社区开发的，是Elasticsearch的Java Http Rest客户端
1.4Spring Data Elasticsearch
spring集成的Elasticsearch开发包
2、RestClient-索引和文档操作
pom:
<dependency><groupId>org.elasticsearch</groupId><artifactId>elasticsearch</artifactId><version>7.6.2</version></dependency><dependency><groupId>org.elasticsearch.client</groupId><artifactId>elasticsearch-rest-high-level-client</artifactId><version>7.6.2</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.13</version></dependency>
java代码：
import static org.junit.Assert.assertTrue;import java.io.IOException;import java.util.Date;import java.util.HashMap;import java.util.Map;import org.apache.http.HttpHost;import org.elasticsearch.action.DocWriteResponse;import org.elasticsearch.action.admin.indices.alias.Alias;import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;import org.elasticsearch.action.admin.indices.open.OpenIndexRequest;import org.elasticsearch.action.admin.indices.open.OpenIndexResponse;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.IndicesOptions;import org.elasticsearch.action.support.master.AcknowledgedResponse;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.CloseIndexRequest;import org.elasticsearch.client.indices.CloseIndexResponse;import org.elasticsearch.client.indices.CreateIndexRequest;import org.elasticsearch.client.indices.CreateIndexResponse;import org.elasticsearch.client.indices.GetIndexRequest;import mon.settings.Settings;import org.junit.Before;import org.junit.FixMethodOrder;import org.junit.Test;import org.junit.runners.MethodSorters;@FixMethodOrder(MethodSorters.NAME_ASCENDING)public class RestHighLevelClientDemo {private RestHighLevelClient client;/*** 创建客户端* * @return*/@Beforepublic void buildClient() {client = new RestHighLevelClient(RestClient.builder(new HttpHost("192.168.1.1.5", 9200, "http")));}/*** 创建索引* @throws IOException*/@Testpublic void test001createIndex() throws IOException {deleteIndex();CreateIndexRequest request = new CreateIndexRequest("person_index");//索引名不能有大写字母，必须全部小写，否则es无法创建索引// 分片配置request.settings(Settings.builder().put("index.number_of_shards", 1).put("index.number_of_replicas", 0));// mapping配置Map<String, Object> name = new HashMap<String, Object>();name.put("type", "text");Map<String, Object> age = new HashMap<String, Object>();age.put("type", "text");Map<String, Object> properties = new HashMap<String, Object>();properties.put("name", name);properties.put("age", age);Map<String, Object> mapping = new HashMap<String, Object>();mapping.put("properties", properties);request.mapping(mapping);// 为索引设置一个别名request.alias(new Alias("person_alias"));CreateIndexResponse createIndexResponse = client.indices().create(request, RequestOptions.DEFAULT);System.out.println(request.index()+"创建索引"+createIndexResponse.isAcknowledged());}/*** 判断索引是否存在* @throws IOException*/@Testpublic void test002existsIndex() throws IOException {GetIndexRequest request = new GetIndexRequest("person_index");request.includeDefaults(true);request.indicesOptions(IndicesOptions.lenientExpandOpen());boolean exists = client.indices().exists(request, RequestOptions.DEFAULT);if (exists) {System.out.println("索引存在");} else {System.out.println("索引不存在");}assertTrue(exists);}/*** 打开索引*/@Testpublic void test003openIndex() {OpenIndexRequest request = new OpenIndexRequest("person_index");try {OpenIndexResponse openIndexResponse = client.indices().open(request, RequestOptions.DEFAULT);boolean acknowledged = openIndexResponse.isAcknowledged();System.out.println("openIndex:"+acknowledged);} catch (IOException e) {e.printStackTrace();}}/**** 关闭索引*/@Testpublic void test004closeIndex() {CloseIndexRequest request = new CloseIndexRequest("person_index"); try {CloseIndexResponse closeIndexResponse = client.indices().close(request, RequestOptions.DEFAULT);boolean acknowledged = closeIndexResponse.isAcknowledged(); System.out.println("closeIndex:"+acknowledged);test003openIndex();} catch (IOException e) {e.printStackTrace();}}/*** 删除索引*/public void deleteIndex() {DeleteIndexRequest request = new DeleteIndexRequest("person_index"); AcknowledgedResponse deleteIndexResponse;try {deleteIndexResponse = client.indices().delete(request, RequestOptions.DEFAULT);boolean acknowledged = deleteIndexResponse.isAcknowledged(); System.out.println("deleteIndex:"+acknowledged);} catch (IOException e) {e.printStackTrace();}}// doc 操作#########################################################################/*** 新增文档* @throws IOException*/@Testpublic void test006insertDoc() throws IOException {Map<String, Object> jsonMap = new HashMap<>();jsonMap.put("user", "kimchy");jsonMap.put("id", new Date().getTime());jsonMap.put("postDate", new Date());jsonMap.put("message", "trying out Elasticsearch22");IndexRequest indexRequest = new IndexRequest("person_index").id("2").source(jsonMap);IndexResponse indexResponse = client.index(indexRequest, RequestOptions.DEFAULT);System.out.println("insertDoc:"+indexResponse.getId());}/*** 查询文档* @throws IOException*/@Testpublic void test007queryDoc() throws IOException {GetRequest getRequest = new GetRequest("person_index", "2");GetResponse getResponse = client.get(getRequest, RequestOptions.DEFAULT);System.out.println("queryDoc:"+getResponse.getSourceAsString());}/*** 更新文档*/@Testpublic void test008updateDoc() {Map<String, Object> jsonMap = new HashMap<>();jsonMap.put("updated", new Date());jsonMap.put("car", "BMW");jsonMap.put("message", "daily update");UpdateRequest request = new UpdateRequest("person_index", "2").doc(jsonMap);try {UpdateResponse updateResponse = client.update(request, RequestOptions.DEFAULT);System.out.println("updateDoc:");} catch (Exception e) {e.printStackTrace();}}/*** 删除文档*/@Testpublic void test009deleteDoc() {DeleteRequest request = new DeleteRequest("person_index", "a06KsXEBRH_WDXoYCFbn");try {DeleteResponse deleteResponse = client.delete(request, RequestOptions.DEFAULT);if (deleteResponse.getResult() == DocWriteResponse.Result.NOT_FOUND) {System.out.println("文档删除成功");}} catch (IOException e) {e.printStackTrace();}}@Testpublic void test010deleteIndex2() {//deleteIndex();}}
