Es官方提供了各种不用语言的客户端，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，从而简化操作
环境准备
我们创建一张hotel-酒店表，然后插入几条数据，基于酒店表做后续的代码书写
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for tb_hotel
-- ----------------------------
DROP TABLE IF EXISTS `tb_hotel`;
CREATE TABLE `tb_hotel` (
`id` bigint 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 NOT NULL COMMENT '酒店价格',
`score` int 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;
-- ----------------------------
-- Records of tb_hotel
-- ----------------------------
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');
SET FOREIGN_KEY_CHECKS = 1;
接下来基于酒店表的数据结构自行分析创建对应的索引表：
PUT /hotel
{
"mappings": {
"properties": {
"all":{
"type": "text",
"analyzer": "ik_max_word"
},
"id":{
"type": "keyword"
},
"name":{
"type": "text",
"analyzer": "ik_smart",
"copy_to": "all"
},
"address":{
"type": "text",
"index": false
},
"price":{
"type": "long",
"index": false
},
"score":{
"type": "keyword"
},
"brand":{
"type": "keyword",
"copy_to": "all"
},
"city":{
"type": "keyword",
"copy_to": "all"
},
"starName":{
"type": "keyword",
"copy_to": "all"
},
"business":{
"type": "keyword",
"index": false
},
"logitude":{
"type": "geo_point"
},
"pic":{
"type": "keyword"
}
}
}
}其中需要注意的是一般搜索酒店会根据名称，城市，评分等多种字段去搜索，每一个字段去创建倒排索引，需要查询很多词，效率低下，于是es支持 我们将这些字段集合到一个自定义的字段中，这个字段不会出现在索引库中，但是查询是按照他来查询。这就是all这个字段的含义。
使用RestClient来操作索引库
1，引入es的RestLevelClient
<!--es依赖-->
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-high-level-client</artifactId>
</dependency>2，修改es版本
因为我们使用的springboot他会综艺的管理依赖，而我们使用的springboot管理的es版本和我们使用的es版本不一致，所以我们需要覆盖springboot的es版本
<properties>
<java.version>1.8</java.version>
<elasticsearch.version>7.12.1</elasticsearch.version>
</properties>3，初始化RestLevelClient
我们这里书写一个测试类完成初始化
@SpringBootTest
public class HotelIndexTest {
private RestHighLevelClient restHighLevelClient;
//初始化es客户端,在代码执行之前先初始化好
@BeforeEach
public void setUp(){
this.restHighLevelClient=new RestHighLevelClient(RestClient.builder(
HttpHost.create("http://192.168.101.100:9200")
));
}
//销毁
@AfterEach
public void close() throws IOException {
restHighLevelClient.close();
}
}
4，使用java代码创建索引库
@Test
void createIndex() throws IOException {
//1,创建request请求对象
CreateIndexRequest request = new CreateIndexRequest("索引库名称");
//2,封装请求参数
request.source(IndexMapping.HotelIndexMapping, XContentType.JSON);
//3，发起请求
restHighLevelClient.indices().create(request, RequestOptions.DEFAULT);
//restHighLevelClient.search()
}5，使用java代码删除索引库
RestClient实现文档增删改查
1，增加一条文档
/**
* 插入一条文档
* @throws IOException
*/
@Test
void insertWord() throws IOException {
Hotel hotel = hotelService.getById(39106);
//创建request请求对象，设置需要插入的文档的索引名，id
IndexRequest indexRequest=new IndexRequest("hotel").id(hotel.getId().toString());
HotelDoc hotelDoc = new HotelDoc(hotel);
//封装请求参数
indexRequest.source(JSON.toJSONString(hotelDoc),XContentType.JSON);
//发起请求
restHighLevelClient.index(indexRequest,RequestOptions.DEFAULT);
}
2，删除一条文档
/**
* 删除一条文档
* @throws IOException
*/
@Test
void deleteWord() throws IOException {
DeleteRequest request=new DeleteRequest("hotel","39106");
DeleteResponse delete = restHighLevelClient.delete(request, RequestOptions.DEFAULT);
System.out.println(delete.getIndex());
}
3，修改一条文档
/**
* 更新文档
* @throws IOException
*/
@Test
void updateWord() throws IOException {
UpdateRequest request=new UpdateRequest("hotel","39106");
Map<String, Object> doc=new HashMap<>();
doc.put("name","修改之后-7天连锁酒店（上海莘庄地铁站店）");
doc.put("price",999);
request.doc(doc);
restHighLevelClient.update(request,RequestOptions.DEFAULT);
}
4，查询一条文档
/**
* 查询一条文档
* @throws IOException
*/
@Test
void searchWord() throws IOException {
//按照id查询文档
GetRequest request=new GetRequest("hotel","39106");
GetResponse response = restHighLevelClient.get(request, RequestOptions.DEFAULT);
String sourceAsString = response.getSourceAsString();
System.out.println(sourceAsString);
//将查询到的json文档重新解析为java对象
HotelDoc hotelDoc = JSON.parseObject(sourceAsString, HotelDoc.class);
System.out.println(hotelDoc);
//输出当前文档属于那个索引库
String index = response.getIndex();
System.out.println("index："+index);
//将每个字段输出 例如 score=41, address=闵行莘庄镇七莘路299号
Map<String, Object> source = response.getSource();
System.out.println("source："+source);
}
5，批量插入多条文档
/**
* 批量插入多条文档
* @throws IOException
*/
@Test
void insertWords() throws IOException {
//只查询十条数据
Page<Hotel> page = new Page<>(2,10);
IPage<Hotel> pageResult = hotelService.page(page);
List<Hotel> hotelList = pageResult.getRecords();
BulkRequest request = new BulkRequest();
hotelList.forEach(hotel -> {
request.add(new IndexRequest("hotel")
.id(hotel.getId().toString())
.source(JSON.toJSONString(hotel),XContentType.JSON));
});
restHighLevelClient.bulk(request,RequestOptions.DEFAULT);
}
至此，使用RestClient对es基本操作完结！！！