ES 7.16 Java API Client 新特性（使用ElasticsearchClient连接操作ES完整demo）

截止7.15版本TransportClient tcp长连接方式，HighLevelRestClient Http rest连接方式官网已淘汰。

使用最新 ElasticsearchClient连接操作ES完整教程：

1、添加依赖

    
      co.elastic.clients
      elasticsearch-java
      7.16.2
    
    
      com.fasterxml.jackson.core
      jackson-databind
      2.12.3
    

2、.properties

# es 服务地址
elasticsearch.clusterNodes=192.168.1.96:9200,192.168.1.97:9200,192.168.1.98:9200

# es 账号
elasticsearch.account=elastic

# es 密码
elasticsearch.passWord=123456

3、连接es集群（根据情况是否设置账号和密码，我这边是需要的）

package com.alcatel.asb.hdm.report.device.util;

import co.elastic.clients.elasticsearch.ElasticsearchClient;
import co.elastic.clients.json.jackson.JacksonJsonpMapper;
import co.elastic.clients.transport.ElasticsearchTransport;
import co.elastic.clients.transport.rest_client.RestClientTransport;
import org.apache.http.HttpHost;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestClientBuilder;

import java.util.Arrays;

/**
 * @author Liner
 * todo ES连接配置工具
 * @date 2021/12/9 21:36
 */
public class EsConfig {

    @Value(value = "${elasticsearch.clusterNodes}")
    private String clusterNodes;//es集群节点 例：//192.168.1.96:9200,192.168.1.97:9200,192.168.1.98:9200

    @Value(value = "${elasticsearch.account}")
    private String account;//账号 例：elastic

    @Value(value = "${elasticsearch.passWord}")
    private String passWord;//密码 例：123456

    public static ElasticsearchClient client;

    //http集群
    public void esClient(){
        HttpHost[] httpHosts = Arrays.stream(clusterNodes.split(",")).map(x -> {
                      String[] hostInfo = x.split(":");
                       return new HttpHost(hostInfo[0], Integer.parseInt(hostInfo[1]));
                   }).toArray(HttpHost[]::new);

        final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
        credentialsProvider.setCredentials(
                AuthScope.ANY, new UsernamePasswordCredentials(account, passWord));//设置账号密码

        RestClientBuilder builder = RestClient.builder(httpHosts)
                .setHttpClientConfigCallback(httpClientBuilder -> httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider));

        // Create the low-level client
        RestClient restClient = builder.build();
        // Create the transport with a Jackson mapper
        ElasticsearchTransport transport = new RestClientTransport(
                restClient, new JacksonJsonpMapper());
        // And create the API client
        client = new ElasticsearchClient(transport);//获取连接

    }
}

3、使用ElasticsearchClient连接查询es

官网现在使用Lambda表达式来进行操作，代码简洁明了很多，缺点就是官网提供的教程太少。

新版本的搜索，根据sql理解为：

select * from logs-itms-nbiproc where timestamp >= startTime and timestamp <= endTime and msg_type = registration or msg_type = activation order by timestamp asc;  

package com.alcatel.asb.hdm.report.device.manager;

import co.elastic.clients.elasticsearch._types.SortOrder;
import co.elastic.clients.elasticsearch.core.SearchResponse;
import co.elastic.clients.elasticsearch.core.search.Hit;
import co.elastic.clients.json.JsonData;
import com.alcatel.asb.hdm.report.device.entity.ESEntity;
import com.alcatel.asb.hdm.report.device.util.EsConfig;

import java.text.SimpleDateFormat;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.util.*;

public class ESChartManagerImpl implements ESChartManager {

    @Override
    public List getESList() {
        String startTime = ZonedDateTime.now().minusHours(1).format(DateTimeFormatter.ISO_INSTANT);
        String endTime = ZonedDateTime.now().format(DateTimeFormatter.ISO_INSTANT);
        System.out.println("开始时间："+startTime);
        System.out.println("结束时间："+endTime);
        Map esMap = new LinkedHashMap<>();
        try {

       // select * from logs-itms-nbiproc where timestamp >= startTime and timestamp <= endTime and msg_type = registration or msg_type = activation order by timestamp asc;  
            SearchResponse