【Elasticsearch-RestClient基础】

时间：2021-08-19 00:58:57
  • 一、认识RestClient
  • ​
  • 二、使用RestClient
    1、基础准备
  • 2、RestClient操作索引库 ... ③ 编写创建索引库方法 ④ 编写删除索引库方法 ⑤ 编写判断是否存在索引库方法 3、RestClient操作文档 ① 添加文档数据方法 ② 获取文档数据方法 ③ 更新文档数据方法 ④ 删除文档数方法 ⑤ 批量操作方法


一、认识RestClient

Java REST Client (deprecated) | ElasticOverview (rest-high-level 7.12.1 API) (elastic.co)

ES官方提供了各种不同语言的客户端，用来操作ES。这些客户端的本质就是组装DSL语句，通过http请求发送给ES。

RestClient是提供给Java的客户端。


二、使用RestClient

1、基础准备

  • ① 创建表格

创建数据表​​tb_hotel​​，如下：


DROP TABLE IF EXISTS `tb_hotel`;
CREATE TABLE `tb_hotel`  (
  `id` bigint(20) NOT NULL COMMENT '酒店id',
  `name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '酒店名称',
  `address` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '酒店地址',
  `price` int(10) NOT NULL COMMENT '酒店价格',
  `score` int(2) NOT NULL COMMENT '酒店评分',
  `brand` varchar(32) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '酒店品牌',
  `city` varchar(32) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '所在城市',
  `star_name` varchar(16) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '酒店星级，1星到5星，1钻到5钻',
  `business` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '商圈',
  `latitude` varchar(32) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '纬度',
  `longitude` varchar(32) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '经度',
  `pic` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '酒店图片',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Compact;

插入数据，如下：


INSERT INTO `tb_hotel` VALUES (36934, '7天连锁酒店(上海宝山路地铁站店)', '静安交通路40号', 336, 37, '7天酒店', '上海', '二钻', '四川北路商业区', '31.251433', '121.47522', 'https://m.tuniucdn.com/fb2/t1/G1/M00/3E/40/Cii9EVkyLrKIXo1vAAHgrxo_pUcAALcKQLD688AAeDH564_w200_h200_c1_t0.jpg');
INSERT INTO `tb_hotel` VALUES (38609, '速8酒店(上海赤峰路店)', '广灵二路126号', 249, 35, '速8', '上海', '二钻', '四川北路商业区', '31.282444', '121.479385', 'https://m.tuniucdn.com/fb2/t1/G2/M00/DF/96/Cii-TFkx0ImIQZeiAAITil0LM7cAALCYwKXHQ4AAhOi377_w200_h200_c1_t0.jpg');
INSERT INTO `tb_hotel` VALUES (38665, '速8酒店上海中山北路兰田路店', '兰田路38号', 226, 35, '速8', '上海', '二钻', '长风公园地区', '31.244288', '121.422419', 'https://m.tuniucdn.com/fb2/t1/G2/M00/EF/86/Cii-Tlk2mV2IMZ-_AAEucgG3dx4AALaawEjiycAAS6K083_w200_h200_c1_t0.jpg');
INSERT INTO `tb_hotel` VALUES (38812, '7天连锁酒店(上海漕溪路地铁站店)', '徐汇龙华西路315弄58号', 298, 37, '7天酒店', '上海', '二钻', '八万人体育场地区', '31.174377', '121.442875', 'https://m.tuniucdn.com/fb2/t1/G2/M00/E0/0E/Cii-TlkyIr2IEWNoAAHQYv7i5CkAALD-QP2iJwAAdB6245_w200_h200_c1_t0.jpg');
INSERT INTO `tb_hotel` VALUES (39106, '7天连锁酒店（上海莘庄地铁站店）', '闵行莘庄镇七莘路299号', 348, 41, '7天酒店', '上海', '二钻', '莘庄工业区', '31.113812', '121.375869', 'https://m.tuniucdn.com/fb2/t1/G2/M00/D8/11/Cii-T1ku2zGIGR7uAAF1NYY9clwAAKxZAHO8HgAAXVN368_w200_h200_c1_t0.jpg');
INSERT INTO `tb_hotel` VALUES (39141, '7天连锁酒店(上海五角场复旦同济大学店)', '杨浦国权路315号', 349, 38, '7天酒店', '上海', '二钻', '江湾、五角场商业区', '31.290057', '121.508804', 'https://m.tuniucdn.com/fb2/t1/G2/M00/C7/E3/Cii-T1knFXCIJzNYAAFB8-uFNAEAAKYkQPcw1IAAUIL012_w200_h200_c1_t0.jpg');
INSERT INTO `tb_hotel` VALUES (416121, '如家酒店(北京西客站北广场店)', '莲花池东路120-2号6层', 275, 43, '如家', '北京', '二钻', '北京西站/丽泽商务区', '39.896449', '116.317382', 'https://m.tuniucdn.com/fb3/s1/2n9c/42DTRnKbiYoiGFVzrV9ZJUxNbvRo_w200_h200_c1_t0.jpg');
  • ② 引入依赖

elasticsearch相关依赖，如下：


<!--elasticsearch-->
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-high-level-client</artifactId>
<version>7.12.1</version>
</dependency>

因为SpringBoot默认的ES版本是7.6.2，所以我们需要覆盖默认的ES版本：


<properties>
<!--指定我们所需的版本，覆盖springboot默认配置-->
<elasticsearch.version>7.12.1</elasticsearch.version>
</properties>

其他依赖，如下：


<!--web-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--mybatis_plus-->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.4.2</version>
</dependency>
<!--mysql_connector-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<!--lombok-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<!--test-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<!--FastJson-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.71</version>
</dependency>
<!--commons-lang3:工具包-->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
</dependency>
  • ③ application.yml

Ⅰ 配置服务端口；
Ⅱ 配置数据源；
Ⅲ 配置日志；
Ⅳ 配置mybatis-plus。


server:
port: 8089
spring:
datasource:
url: jdbc:mysql://localhost:3306/test?useSSL=false
username: root
password: root
driver-class-name: com.mysql.jdbc.Driver
logging:
level:
cn.test: debug
pattern:
dateformat: MM-dd HH:mm:ss:SSS
mybatis-plus:
configuration:
map-underscore-to-camel-case: true
type-aliases-package: cn.test.hotel.pojo
  • ④ 编写实体类

Hotel类


@Data
@TableName("tb_hotel")
public class Hotel {
    @TableId(type = IdType.INPUT)
    private Long id;
    private String name;
    private String address;
    private Integer price;
    private Integer score;
    private String brand;
    private String city;
    private String starName;
    private String business;
    private String longitude;
    private String latitude;
    private String pic;
}

HotelDoc类


@Data
@NoArgsConstructor
public class HotelDoc {
private Long id;
private String name;
private String address;
private Integer price;
private Integer score;
private String brand;
private String city;
private String starName;
private String business;
private String location;
private String pic;

public HotelDoc(Hotel hotel) {
this.id = hotel.getId();
this.name = hotel.getName();
this.address = hotel.getAddress();
this.price = hotel.getPrice();
this.score = hotel.getScore();
this.brand = hotel.getBrand();
this.city = hotel.getCity();
this.starName = hotel.getStarName();
this.business = hotel.getBusiness();
this.location = hotel.getLatitude() + ", " + hotel.getLongitude();
this.pic = hotel.getPic();
    }
}

geo_point类型属性映射的形式有多种，官方文档见此：Geopoint field type ，常见的形式如下图。此处我们采用第2种形式，做属性映射"location": "41.12,-71.34"，所以在类型转换的时候手动拼接了属性值this.location = hotel.getLatitude() + ", " + hotel.getLongitude();。

【Elasticsearch-RestClient基础】


  • ⑤ 编写mapper接口及service接口&实现类


public interface HotelMapper extends BaseMapper<Hotel> {
}

public interface IHotelService extends IService<Hotel> {
}

@Service
public class HotelService extends ServiceImpl<HotelMapper, Hotel> implements IHotelService {
}

2、RestClient操作索引库

  • ① 创建索引库

Ⅰ 编写创建索引库语句：这个步骤可以在自己Dev Tools控制台内完成，然后将字段复制到IDEA。


public class HotelConstant {

public static final String MAPPING_TEMPLATE = "" +
"{\n" +
"  \"mappings\": {\n" +
"    \"properties\": {\n" +
"      \"id\":{\n" +
"        \"type\": \"keyword\"\n" +
"      },\n" +
"      \"name\":{\n" +
"        \"type\": \"text\",\n" +
"        \"analyzer\": \"ik_max_word\",\n" +
"        \"copy_to\": \"all\"\n" +
"      },\n" +
"      \"address\":{\n" +
"        \"type\": \"keyword\",\n" +
"        \"index\": false\n" +
"      },\n" +
"      \"price\":{\n" +
"        \"type\": \"integer\"\n" +
"      },\n" +
"      \"score\":{\n" +
"        \"type\": \"integer\"\n" +
"      },\n" +
"      \"brand\":{\n" +
"        \"type\": \"keyword\",\n" +
"        \"copy_to\": \"all\"\n" +
"      },\n" +
"      \"city\":{\n" +
"        \"type\": \"keyword\"\n" +
"      },\n" +
"      \"starName\":{\n" +
"        \"type\":\"keyword\"\n" +
"      },\n" +
"      \"business\":{\n" +
"        \"type\": \"keyword\",\n" +
"        \"copy_to\": \"all\"\n" +
"      },\n" +
"      \"location\":{\n" +
"        \"type\": \"geo_point\"\n" +
"      },\n" +
"      \"pic\":{\n" +
"        \"type\": \"keyword\",\n" +
"        \"index\": false\n" +
"      },\n" +
"      \"all\":{\n" +
"        \"type\": \"text\",\n" +
"        \"analyzer\": \"ik_max_word\"\n" +
"      }\n" +
"    }\n" +
"  }\n" +
"}";

}
  • ② 编写测试类

​​@BeforeEach​​内完成client对象的初始化配置，​​@AfterEach​​内完成操作后的资源释放。


public class HotelIndexTest {

private RestHighLevelClient client;

@BeforeEach
void setUp(){
this.client = new RestHighLevelClient(RestClient.builder(
HttpHost.create("http://192.168.253.128:9200")
        ));
    }

    ... ...

@AfterEach
void tearDown(){
try {
this.client.close();
        } catch (IOException e) {
e.printStackTrace();
        }
    }
}
  • ③ 编写创建索引库方法


@Test
void createHotelIndex(){
// 1. 创建Request对象
CreateIndexRequest request = new CreateIndexRequest("hotel");
// 2. 准备请求参数DSL语句
request.source(HotelConstant.MAPPING_TEMPLATE, XContentType.JSON);
// 3. 发送请求
try {
client.indices().create(request, RequestOptions.DEFAULT);
        } catch (IOException e) {
e.printStackTrace();
        }
    }

【Elasticsearch-RestClient基础】


  • ④ 编写删除索引库方法


@Test
void deleteHotelIndex(){
// 1. 创建Request对象
DeleteIndexRequest request = new DeleteIndexRequest("hotel");
// 2. 发送请求
try {
client.indices().delete(request, RequestOptions.DEFAULT);
        } catch (IOException e) {
e.printStackTrace();
        }
    }
  • ⑤ 编写判断是否存在索引库方法


@Test
void existsHotelIndex(){
// 1. 创建Request对象
GetIndexRequest request = new GetIndexRequest("hotel");
// 2. 发送请求
try {
boolean exists = client.indices().exists(request, RequestOptions.DEFAULT);
System.err.println(exists ? "hotel index exists!" : "hotel index not exist!");
        } catch (IOException e) {
e.printStackTrace();
        }
    }


不难看出对索引库的操作有一定的相似性：
Ⅰ XXXIndexRequest：Create、Delete、Get的请求request对象；

Ⅱ client.indices().XXX()：create、delete、get方法。

3、RestClient操作文档

添加@SpringBootTest注解，注入hotelService：


@Resource
private IHotelService hotelService;
  • ① 添加文档数据方法


@Test
void addDocument(){
// 1. 查询数据库
Hotel hotel = hotelService.getById(36934L);
// 2. 封装成DOC对象
HotelDoc hotelDoc = new HotelDoc(hotel);
// 3. 获取request对象
IndexRequest request = new IndexRequest("hotel").id(hotel.getId().toString());
// 4. 将数据放入request
request.source(JSON.toJSONString(hotelDoc), XContentType.JSON);
// 5. 存储数据
try {
client.index(request, RequestOptions.DEFAULT);
        } catch (IOException e) {
e.printStackTrace();
        }
    }
  • ② 获取文档数据方法


@Test
void getDocumentById(){
// 1. 创建request对象
GetRequest request = new GetRequest("hotel", "36934");
try {
// 2. 发送请求，得到结果
GetResponse response = client.get(request, RequestOptions.DEFAULT);
// 3. 解析结果
String json = response.getSourceAsString();

System.out.println(json);
        } catch (IOException e) {
e.printStackTrace();
        }
    }
  • ③ 更新文档数据方法


@Test
void updateDocumentById(){
// 1. 创建request对象
UpdateRequest request = new UpdateRequest("hotel", "36934");
// 2. 设置更新字段
request.doc(
"price", "346",
"starName", "三钻"
        );
// 3. 更新文档
try {
client.update(request, RequestOptions.DEFAULT);
        } catch (IOException e) {
e.printStackTrace();
        }
    }
  • ④ 删除文档数方法


@Test
void deleteDocumentById(){
// 1. 创建request对象
DeleteRequest request = new DeleteRequest("hotel", "36934");
// 2. 删除文档
try {
client.delete(request, RequestOptions.DEFAULT);
        } catch (IOException e) {
e.printStackTrace();
        }
    }
  • ⑤ 批量操作方法


@Test
void bulkRequest(){
// 1. 获取请求对象
BulkRequest request = new BulkRequest();
// 2. 准备参数，添加多个新增的Request
// 2.1 批量获取数据库的数据
List<Hotel> hotelList = hotelService.list();
for (int i = 0; i < hotelList.size(); i++) {
// 2.2 获取hotel对象
Hotel hotel = hotelList.get(i);
// 2.3 转换成hotelDoc对象
HotelDoc hotelDoc = new HotelDoc(hotel);
/*// 2.4 获取request对象
IndexRequest indexRequest = new IndexRequest("hotel").id(hotel.getId().toString());
// 2.5 将数据放入request
indexRequest.source(JSON.toJSONString(hotelDoc), XContentType.JSON);
// 2.6 将indexRequest对象加入request
request.add(indexRequest);*/
request.add(new IndexRequest("hotel")
                    .id(hotelDoc.getId().toString())
                    .source(JSON.toJSONString(hotelDoc), XContentType.JSON));
        }
// 3. 批量添加
try {
client.bulk(request, RequestOptions.DEFAULT);
        } catch (IOException e) {
e.printStackTrace();
        }
    }

不难看出对索引文档的操作也具有一定的相似性：

Ⅰ XXXRequest：Index、Get、Update、Delete、Bulk的请求request对象；

Ⅱ client.XXX(方法：index、get、update、delete、bulk方法。


三、结尾

以上即为RestClient基础的全部内容


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