Elasticsearch 之（46） Java API 基于mget实现多辆汽车的配置与价格对比

场景，一般来说，我们都可以在一些汽车网站上，或者在混合销售多个品牌的汽车4S店的内部，都可以在系统里调出来多个汽车的信息，放在网页上，进行对比

mget，一次性将多个document的数据查询出来，放在一起显示，多个汽车的型号，一次性拿出了多辆汽车的信息

package com.es.app;


import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.action.get.MultiGetItemResponse;
import org.elasticsearch.action.get.MultiGetResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.update.UpdateRequest;
import org.elasticsearch.action.update.UpdateResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.InetSocketTransportAddress;
import org.elasticsearch.common.xcontent.XContentFactory;
import org.elasticsearch.transport.client.PreBuiltTransportClient;

import java.net.InetAddress;

public class MgetCarInfoApp {

    public static void main(String[] args) throws Exception {
        Settings settings = Settings.builder()
                .put("cluster.name", "elasticsearch")
                .put("client.transport.sniff", true)
                .build();

        TransportClient client = new PreBuiltTransportClient(settings)
                .addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("localhost"), 9300));

        MultiGetResponse multiGetItemResponses = client.prepareMultiGet()
                .add("car_shop", "cars", "1")
                .add("car_shop", "cars", "2")
               .get();

        for (MultiGetItemResponse multiGetItemResponse : multiGetItemResponses) {
            GetResponse getResponse = multiGetItemResponse.getResponse();
            if(getResponse.isExists()){
               String json = getResponse.getSourceAsString();
                System.out.println(json);
            }
        }
    }

}

{"brand":"宝马","name":"宝马320","price":310000,"produce_date":"2017-01-01"}
{"brand":"宝马","name":"宝马310","price":310000,"produce_date":"2017-02-02"}