Java最新JAVA API调用elasticsearch实现基本增删改查，java面试逻辑题答案

import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestClientBuilder;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.get.GetRequest;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.action.update.UpdateRequest;
import org.elasticsearch.action.update.UpdateResponse;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.search.builder.SearchSourceBuilder;
 
public class ElasticSearchExample {
 
    private RestHighLevelClient client;
 
    public ElasticSearchExample(String hostname, int port) {
        this.client = new RestHighLevelClient(
            RestClient.builder(new HttpHost(hostname, port, "http")));
    }
 
    public void indexDocument() throws IOException {
        IndexRequest request = new IndexRequest("index_name", "doc", "1");
        request.source("field", "value");
        IndexResponse response = client.index(request, RequestOptions.DEFAULT);
    }
 
    public void getDocument() throws IOException {
        GetRequest request = new GetRequest("index_name", "doc", "1");
        GetResponse response = client.get(request, RequestOptions.DEFAULT);
    }
 
    public void updateDocument() throws IOException {
        UpdateRequest request = new UpdateRequest("index_name", "doc", "1");
        request.doc("field", "new_value");
        UpdateResponse response = client.update(request, RequestOptions.DEFAULT);
    }
 
    public void deleteDocument() throws IOException {
        DeleteRequest request = new DeleteRequest("index_name", "doc", "1");
        DeleteResponse response = client.delete(request, RequestOptions.DEFAULT);
    }
 
    public void closeClient() throws IOException {
        client.close();
    }
 
    public static void main(String[] args) {
        ElasticSearchExample example = new ElasticSearchExample("localhost", 9200);
        try {
            // 创建文档
            example.indexDocument();
            // 获取文档
            example.getDocument();
            // 更新文档
            example.updateDocument();