1.Jest介绍
操作Elasticsearch的客户端有很多,SpringBoot也提供了方式去操作,这里介绍另外一种方式去使用Elasticsearch --- JestClient
JestClient是一款基于HTTP方式操作的Elasticsearch的客户端,支持同步和异步操作,同时也可以结合ElasticSearch的依赖进行操作Elasticsearch。
支持多个版本的Elasticsearch,如下:
= 6.0.0 | 6
= 5.0.0 | 5
= 2.0.0 | 2
0.1.0 - 1.0.0 | 1
<= 0.0.6 | < 1
更多信息可以查看github,地址是:https://github.com/searchbox-io/Jest
2.SpringBoot整合JestClient
接下来介绍如何在SpringBoot中使用JestClient操作Elasticsearch。
2.1 前置工作
首先启动Elasticsearch,我这里是在本地启动的Elasticsearch,版本是6.8.2,为了方便查看数据,这里使用Elasticsearch-Head插件,如下图所示。
2.2 添加Jest依赖
创建项目,在pom文件中加入Jest依赖(这里根据上面版本对应添加依赖),这里额外添加量了elasticsearch和lombok为了方便操作,如下:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.dalaoyang</groupId>
<artifactId>springboot_jestclient</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>springboot_jestclient</name>
<description>springboot_jestclient</description>
<properties>
<java.version>1.8</java.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<spring-boot.version>2.2.6.RELEASE</spring-boot.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<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>
<dependency>
<groupId>io.searchbox</groupId>
<artifactId>jest</artifactId>
<version>6.3.1</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.16.10</version>
</dependency>
<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
<version>6.8.2</version>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-dependencies</artifactId>
<version>${spring-boot.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<version>2.2.6.RELEASE</version>
</plugin>
</plugins>
</build>
</project>
2.3 配置文件
在配置文件中添加elasticsearch相关配置,其中uris配置Elasticsearch的HTTP端口,如本文添加的配置:
spring.application.name=springboot_jestclient
# 应用服务web访问端口
server.port=8888
spring.elasticsearch.rest.uris=http://localhost:9200
spring.elasticsearch.jest.username=elastic
spring.elasticsearch.jest.password=elastic
到这里其实已经整合完成了,是不是非常简单?
3.Elasticsearch基本操作
接下介绍如何操作Elasticsearch,这里分别介绍如下几部分内容:
- 索引文档
- 索引类操作
- 文档类操作
- 查询操作
3.1 文档实体
这里创建一个Book文档做为示例,其中@JestId为文档id,即Elasticsearch中的_id字段,本文BookDocument内容如下:
package com.dalaoyang.document;
import io.searchbox.annotations.JestId;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class BookDocument {
@JestId
private String id;
private String bookName;
private String bookAuthor;
private Integer pages;
private String desc;
}
为了方便操作,这里创建了一个request对象进行操作,如下:
package com.dalaoyang.model;
import com.dalaoyang.document.BookDocument;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class BookRequest {
//删除文档用
private String id;
//查询用
private String keyword;
private String indexName;
private String typeName;
//新增文档用
private BookDocument body;
}
在使用相关操作时,其实都是通过io.searchbox.client.JestClient#execute来进行操作(需要注意,这里没有对JestClient进行配置,只是使用的默认的配置),将对应动作当做参数传入,接下来介绍几个常用的动作。
3.2 索引类操作
结合MySQL来看的话,索引可以理解为一个数据库,索引相关的操作可能不是很多,这里介绍相对比较常用的是创建索引和删除索引,如下:
3.2.1 创建索引
CreateIndex createIndex = new CreateIndex.Builder(indexName).build();
3.2.2 删除索引
DeleteIndex deleteIndex = new DeleteIndex.Builder(indexName).build();
通过上面两个操作可以看到,都是通过使用对应的Index实体来操作对应实体,当然还有一些不是很常用的,如果有需要可以查看相关文档进行使用,这里不一一介绍了,完整s示例内容如下:
package com.dalaoyang.web;
import io.searchbox.client.JestClient;
import io.searchbox.client.JestResult;
import io.searchbox.indices.CreateIndex;
import io.searchbox.indices.DeleteIndex;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class IndexController {
@Autowired
private JestClient jestClient;
@GetMapping("createIndex")
public String createIndex(String indexName) throws Exception{
CreateIndex createIndex = new CreateIndex.Builder(indexName).build();
JestResult result = jestClient.execute(createIndex);
return result.getJsonString();
}
@GetMapping("deleteIndex")
public String deleteIndex(String indexName) throws Exception{
DeleteIndex deleteIndex = new DeleteIndex.Builder(indexName).build();
JestResult result = jestClient.execute(deleteIndex);
return result.getJsonString();
}
}
3.3 文档类操作
文档相当于MySQL中的行记录,也就是说一条数据,由于新增和修改在同一个方法内,所以这里也是对新增(和修改)和删除方法进行介绍,如下:
3.3.1 新增或修改文档
首先会判断索引是否存在,不存在的话会根据索引文档进行创建索引,然后进行新增或修改操作,如果没有指定id的话(上文说的注解@JestId字段),会自动生成一个id。
Index.Builder builder = new Index.Builder(bookRequest.getBody());
Index index = builder.index(bookRequest.getIndexName()).type(bookRequest.getTypeName()).build();
这里使用新增文档创建三条数据方便后面查询,如下:
{
"indexName": "book",
"typeName": "book",
"body": {"id":"test0001","bookName":"数学书","bookAuthor":"复旦大学","pages":100,"desc":"复旦大学的数学书"}
}
{
"indexName": "book",
"typeName": "book",
"body": {"id":"test0003","bookName":"语文书","bookAuthor":"北京大学","pages":100,"desc":"北京大学的语文书"}
}
{
"indexName": "book",
"typeName": "book",
"body": {"id":"test0003","bookName":"英文书","bookAuthor":"清华大学","pages":200,"desc":"清华大学的英文书"}
}
3.3.2 删除文档(根据id)
Delete index = new Delete.Builder(bookRequest.getId()).index(bookRequest.getIndexName()).type(bookRequest.getTypeName()).build();
完整示例内容如下:
package com.dalaoyang.web;
import com.dalaoyang.model.BookRequest;
import io.searchbox.client.JestClient;
import io.searchbox.client.JestResult;
import io.searchbox.core.Delete;
import io.searchbox.core.Index;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class DocumentController {
@Autowired
private JestClient jestClient;
@PostMapping("saveOrUpdateDocument")
public String saveOrUpdateDocument(@RequestBody BookRequest bookRequest) throws Exception{
Index.Builder builder = new Index.Builder(bookRequest.getBody());
Index index = builder.index(bookRequest.getIndexName()).type(bookRequest.getTypeName()).build();
JestResult result = jestClient.execute(index);
return result.getJsonString();
}
@PostMapping("deleteDocumentById")
public String deleteDocumentById(@RequestBody BookRequest bookRequest) throws Exception{
Delete index = new Delete.Builder(bookRequest.getId()).index(bookRequest.getIndexName()).type(bookRequest.getTypeName()).build();
JestResult result = jestClient.execute(index);
return result.getJsonString();
}
}
3.4 查询操作
查询操作可能是对Elasticsearch最需要使用的场景,这里举一个简单的场景,输入关键字,查询对应book文档,关键字匹配(bookName,bookAuthor,desc)三个字段,这里结合Elasticsearch官方依赖进行操作,完整示例如下:
package com.dalaoyang.web;
import com.dalaoyang.model.BookRequest;
import io.searchbox.client.JestClient;
import io.searchbox.core.Search;
import io.searchbox.core.SearchResult;
import lombok.extern.slf4j.Slf4j;
import org.elasticsearch.index.query.MultiMatchQueryBuilder;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
@RestController
@Slf4j
public class QueryController {
@Autowired
private JestClient jestClient;
@PostMapping("search")
public String search(@RequestBody BookRequest bookRequest) throws Exception{
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.query(new MultiMatchQueryBuilder(bookRequest.getKeyword(), "bookName","bookAuthor","desc"));
log.info(searchSourceBuilder.toString());
SearchResult result = jestClient.execute(new Search.Builder(searchSourceBuilder.toString())
.addIndex(bookRequest.getIndexName())
.addType(bookRequest.getTypeName())
.build());
return result.getJsonString();
}
}
比如这里搜索清华,这里我打印了一下查询语句,如下:
{
"query":{
"multi_match":{
"query":"清华",
"fields":[
"bookAuthor^1.0",
"bookName^1.0",
"desc^1.0"
],
"type":"best_fields",
"operator":"OR",
"slop":0,
"prefix_length":0,
"max_expansions":50,
"zero_terms_query":"NONE",
"auto_generate_synonyms_phrase_query":true,
"fuzzy_transpositions":true,
"boost":1
}
}
}
查询的结构只有一条,与在Elasticsearch-Head中查询一致,如图
4.一些建议
相关操作Elasticsearch的客户端有很多,这里就不做相关对比了,JestClient本人也在真实上线项目中使用过,这里只是在使用过几种的前提下做出几点建议:
- Elastic官方已经开始建议使用HTTP方式去操作Elasticsearch了
- 当初选择这种的原因是考虑到更好的去扩展版本,封装响应的操作类可以兼容更多的版本。
- 在高版本的Elasticsearch中,有一些文档类型的内容被单独抽离出来了,比如父子文档。
5.源码
源码地址:https://gitee.com/dalaoyang/springboot_learn/tree/master/springboot_jestclient