ES客户端分类

Es-Server提供RESTFul-Api，客户端通过发起http请求，调用api实现索引库的管理，数据的交换，server端状态的监控......

• 官方java客户端：

    org.elasticsearch.client
    elasticsearch-rest-client
    7.15.2
 

• SpringDataElasticSearch：

    
    org.springframework.boot    
    spring-boot-starter-data-elasticsearch

SpringDataElasticSearch继承了官方客户端elasticsearch-rest-client

• Elasticsearch.Net
• devtool：kibana
• HttpClient
• postman
• ......

特殊的客户端，节点客户端（NodeClient），将自己作为Es-server集群的节点。

SpringDataElasticsearch

• ElasticsearchRepository
• ElasticsearchRestTemplate
• ElasticsearchOperations

ElasticsearchRestTemplate继承了ElasticsearchOperations，一般开发中都是基于ElasticsearchRestTemplate来访问ES服务端。

ElasticsearchRestTemplate

环境

• ES-Server：7.14.0
• SpringBoot：2.5.3
• spring-boot-starter-data-elasticsearch：2.5.3
• Spring Data Elasticsearch: 4.2.3
• Elasticsearch Client used: 7.12.1
• Elasticsearch cluster: 7.14.0
• 测试索引库名称：vehicle
• 索引库数据结构：

 {
                "_index": "vehicle",
                "_type": "_doc",
                "_id": "19771755968",
                "_version": 1,
                "_score": 1.0,
                "_source": {
                    "id": 19771755968,
                    "crossing_id": 30474,
                    "plate_number": "沪D86447",
                    "plate_color": "黄色",
                    "is_valid": 1,
                    "snap_time": "2021-08-29 08:00:00",
                    "create_time": "2021-08-29 08:07:51",
                    "lane_number": 1,
                    "crossing_timestamp": 1630195671.0
                }
   }

• 索引库映射：

{
    "vehicle": {
        "mappings": {
            "properties": {
                "create_time": {
                    "type": "date",
                    "format": "yyyy-MM-dd HH:mm:ss||yyyy-MM-dd||epoch_millis"
                },
                "crossing_id": {
                    "type": "keyword"
                },
                "crossing_timestamp": {
                    "type": "long"
                },
                "id": {
                    "type": "keyword"
                },
                "is_valid": {
                    "type": "keyword"
                },
                "lane_number": {
                    "type": "keyword"
                },
                "plate_color": {
                    "type": "keyword"
                },
                "plate_number": {
                    "type": "keyword"
                },
                "snap_time": {
                    "type": "date",
                    "format": "yyyy-MM-dd HH:mm:ss||yyyy-MM-dd||epoch_millis"
                }
            }
        }
    }
}

引入pom依赖

   
        org.springframework.boot
        spring-boot-starter-data-elasticsearch
    
    
        com.alibaba
        fastjson
        1.2.71
    
    
    org.springframework.boot
    spring-boot-starter-web


    org.projectlombok
    lombok
    true

配置ES-Server地址

application.yml

spring:
elasticsearch:
  rest:
    uris: http://192.168.1.149:19200

定义model

import com.fasterxml.jackson.annotation.JsonFormat;
import lombok.Data;
import lombok.experimental.Accessors;
import org.springframework.data.annotation.Id;
import org.springframework.data.elasticsearch.annotations.DateFormat;
import org.springframework.data.elasticsearch.annotations.Document;
import org.springframework.data.elasticsearch.annotations.Field;
import org.springframework.data.elasticsearch.annotations.FieldType;
import java.io.Serializable;
import java.time.LocalDateTime;



@Accessors(chain = true)
@Data
@Document(indexName = "vehicle")
public class Vehicle implements Serializable {
    @Id
    private String id;
    @Field("plate_number")
    private String plateNumber;
    @Field("plate_color")
    private String plateColor;
    @Field("is_valid")
    private Integer valid;
    @Field("lane_number")
    private Integer laneNumber;
    @Field(name = "create_time", type = FieldType.Date, format = DateFormat.custom, pattern = "uuuu-MM-dd HH:mm:ss")
    private LocalDateTime createTime;
    @Field("crossing_id")
    private Long crossingId;
    @Field("crossing_timestamp")
    private Long crossingTimestamp;
    private  Long sum;
}

根据id查询

@Autowiredprivate ElasticsearchRestTemplate template;


@GetMapping("/{id}")
public Vehicle getVehicle(@PathVariable("id") String id) {
    Vehicle vehicle = template.get(id, Vehicle.class);
    return vehicle;
}

list查询

@Autowiredprivate ElasticsearchRestTemplate template;


@PostMapping("/list")
public List findVehicle(@RequestBody FindVehicleParam param) {
    NativeSearchQuery query = new NativeSearchQueryBuilder()
            .withQuery(QueryBuilders.matchQuery("plate_number", param.getPlateNumber()))
            .withQuery(null != param.getPlateColor() ? QueryBuilders.matchQuery("plate_color", param.getPlateColor()) : null)
            .build();
    SearchHits result = template.search(query, Vehicle.class);
    List lists = result.getSearchHits().stream().map(SearchHit::getContent).collect(Collectors.toList());
    return lists;
}

查询过滤

@Autowiredprivate ElasticsearchRestTemplate template;

@PostMapping("/filter")
public List findVehicleWithFilter(@RequestBody FindVehicleParam param) {
    NativeSearchQuery query = new NativeSearchQueryBuilder()
            .withQuery(QueryBuilders.matchQuery("plate_number", param.getPlateNumber()))
            .withQuery(null != param.getPlateColor() ? QueryBuilders.matchQuery("plate_color", param.getPlateColor()) : null)
            //crossing_id 大于 2000
            .withFilter(QueryBuilders.rangeQuery("crossing_id").gt(2000))
            .build();
    SearchHits result = template.search(query, Vehicle.class);
    List lists = result.getSearchHits().stream().map(SearchHit::getContent).collect(Collectors.toList());
    return lists;
}

查询聚合

@Autowiredprivate ElasticsearchRestTemplate template;

@PostMapping("/agg")
public VehicleAggregationDto findVehicleWithAgg(@RequestBody FindVehicleParam param) {
    VehicleAggregationDto vehicleAggregationDto = new VehicleAggregationDto();
    NativeSearchQuery query = new NativeSearchQueryBuilder()
            .withQuery(QueryBuilders.matchQuery("plate_number", param.getPlateNumber()))
            .withQuery(null != param.getPlateColor() ? QueryBuilders.matchQuery("plate_color", param.getPlateColor()) : null)
            //crossing_id 大于 2000
            .withFilter(QueryBuilders.rangeQuery("crossing_id").gt(2000))
            .addAggregation(AggregationBuilders.sum("sumCrossingTimestamp").field("crossing_timestamp"))
            .addAggregation(AggregationBuilders.sum("sumCreateTime").field("create_time"))
            .withPageable(PageRequest.of(0, 50))
            .build();
    SearchHits result = template.search(query, Vehicle.class);
    List lists = result.getSearchHits().stream().map(SearchHit::getContent).collect(Collectors.toList());
    vehicleAggregationDto.setVehicles(lists);
    Map agg = new ConcurrentHashMap<>();
    result.getAggregations().getAsMap().forEach((key, value) -> {
        agg.put(key, ((Sum) value).getValue());
    });
    vehicleAggregationDto.setAggregation(agg);
    return vehicleAggregationDto;
}

分页

@Autowiredprivate ElasticsearchRestTemplate template;

@PostMapping("/page")
public List findVehiclePage(@RequestBody FindVehiclePageParam param) {
    NativeSearchQuery query = new NativeSearchQueryBuilder()
//                .withQuery(QueryBuilders.matchAllQuery())
            .withQuery(QueryBuilders.matchQuery("plate_number", param.getPlateNumber()))
            .withPageable(PageRequest.of(0, param.getPageSize()))
            .withSort(SortBuilders.fieldSort("id"))
            .build();
    SearchHits result = template.search(query, Vehicle.class);
    List lists = result.getSearchHits().stream().map(SearchHit::getContent).collect(Collectors.toList());
    return lists;
}

引用

• 官网：https://www.elastic.co/guide/en/elasticsearch/client/java-rest/7.15/java-rest-low-usage-maven.html
• SpringDataElasticsearch官网：https://docs.spring.io/spring-data/elasticsearch/docs/current/reference/html/#elasticsearch.clients.rest