java与es8实战之四：SpringBoot应用中操作es8(无安全检查)

技术分享 3年前 (2023-08-30) 0 999+

关注

欢迎访问我的GitHub

这里分类和汇总了欣宸的全部原创(含配套源码)：https://github.com/zq2599/blog_demos

本篇概览

本篇是《java与es8实战》系列的第四篇，系列文章写到现在，连个HelloWorld都没运行起来，实在说不过去了...
因此，本篇总体目标明确：实战在SpringBoot应用中操作elasticsearch8
为了降低难度，本篇部署的elasticsearch8未设置安全检查，无需证书、账号、密码，只要连接到es的IP和端口就能执行操作
总体目标可以拆解为两个子任务

在SpringBoot中连接elasticsearch8
在SpringBoot中使用elasticsearch8官方的Java API Client

接下来直接开始

部署elasticsearch集群(无安全检查)

关于快速部署elasticsearch集群(无安全检查)，可以参考《docker-compose快速部署elasticsearch-8.x集群+kibana》

Java应用连接elasticsearch的核心套路

不论是直连，还是带安全检查的连接，亦或是与SpringBoot的集成使之更方便易用，都紧紧围绕着一个不变的核心套路，该套路由两部分组成，掌握了它们就能在各种条件下成功连接es

首先，是builder pattern，连接es有关的代码，各种对象都是其builder对象的build方法创建的，建议您提前阅读《java与es8实战之一》一文，看完后，满屏的builder代码可以从丑变成美...
其次，就是java应用能向es发请求的关键：ElasticsearchClient对象，该对象的创建是有套路的，如下图，先创建RestClient，再基于RestClient创建ElasticsearchTransport，最后基于ElasticsearchTransport创建ElasticsearchClient，这是个固定的套路，咱们后面的操作都是基于此的，可能会加一点东西，但不会改变流程和图中的对象

准备完毕，开始写代码

新建子工程

为了便于管理依赖库版本和源码，《java与es8实战》系列的所有代码都以子工程的形式存放在父工程elasticsearch-tutorials中
《java与es8实战之二：实战前的准备工作》一文说明了创建父工程的详细过程
在父工程elasticsearch-tutorials中新建名为basic-crud的子工程，其pom.xml内容如下

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">     <!-- 请改为自己项目的parent坐标 -->     <parent>         <artifactId>elasticsearch-tutorials</artifactId>         <groupId>com.bolingcavalry</groupId>         <version>1.0-SNAPSHOT</version>         <relativePath>../pom.xml</relativePath>     </parent>     <modelVersion>4.0.0</modelVersion>     <!-- 请改为自己项目的artifactId -->     <artifactId>basic-crud</artifactId>     <packaging>jar</packaging>     <!-- 请改为自己项目的name -->     <name>basic-crud</name>     <url>https://github.com/zq2599</url>      <!--不用spring-boot-starter-parent作为parent时的配置-->     <dependencyManagement>         <dependencies>             <dependency>                 <groupId>org.springframework.boot</groupId>                 <artifactId>spring-boot-dependencies</artifactId>                  <version>${springboot.version}</version>                 <type>pom</type>                 <scope>import</scope>             </dependency>         </dependencies>     </dependencyManagement>      <dependencies>         <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-actuator</artifactId>         </dependency>          <!-- 不加这个，configuration类中，IDEA总会添加一些提示 -->         <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-configuration-processor</artifactId>             <optional>true</optional>         </dependency>          <dependency>             <groupId>org.projectlombok</groupId>             <artifactId>lombok</artifactId>         </dependency>          <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>              <!-- exclude junit 4 -->             <exclusions>                 <exclusion>                     <groupId>junit</groupId>                     <artifactId>junit</artifactId>                 </exclusion>             </exclusions>          </dependency>          <!-- junit 5 -->         <dependency>             <groupId>org.junit.jupiter</groupId>             <artifactId>junit-jupiter-api</artifactId>             <scope>test</scope>         </dependency>          <dependency>             <groupId>org.junit.jupiter</groupId>             <artifactId>junit-jupiter-engine</artifactId>             <scope>test</scope>         </dependency>          <!-- elasticsearch引入依赖  start -->         <dependency>             <groupId>co.elastic.clients</groupId>             <artifactId>elasticsearch-java</artifactId>         </dependency>          <dependency>             <groupId>com.fasterxml.jackson.core</groupId>             <artifactId>jackson-databind</artifactId>         </dependency>          <!-- 使用spring boot Maven插件时需要添加该依赖 -->         <dependency>             <groupId>jakarta.json</groupId>             <artifactId>jakarta.json-api</artifactId>         </dependency>          <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-web</artifactId>         </dependency>     </dependencies>      <build>         <plugins>             <!-- 需要此插件，在执行mvn test命令时才会执行单元测试 -->             <plugin>                 <groupId>org.apache.maven.plugins</groupId>                 <artifactId>maven-surefire-plugin</artifactId>                 <version>3.0.0-M4</version>                 <configuration>                     <skipTests>false</skipTests>                 </configuration>             </plugin>              <plugin>                 <groupId>org.springframework.boot</groupId>                 <artifactId>spring-boot-maven-plugin</artifactId>                 <configuration>                     <excludes>                         <exclude>                             <groupId>org.projectlombok</groupId>                             <artifactId>lombok</artifactId>                         </exclude>                     </excludes>                 </configuration>             </plugin>         </plugins>          <resources>             <resource>                 <directory>src/main/resources</directory>                 <includes>                     <include>**/*.*</include>                 </includes>             </resource>         </resources>     </build> </project>

编码：配置文件

先准备好配置文件application.yml，内容如下，很简单，只有es的地址信息

elasticsearch:   # 多个IP逗号隔开   hosts: 127.0.0.1:9200

编码：配置类

首先把启动类写好，平平无奇的启动类BasicCrudApplication.java

@SpringBootApplication public class BasicCrudApplication {     public static void main(String[] args) {         SpringApplication.run(BasicCrudApplication.class, args);     } }

然后是配置类ClientConfig.java，这是本篇的关键，操作ES所需的ElasticsearchClient实例如何创建，ES的IP地址如何传入，全部写在这里了

package com.bolingcavalry.basic.config;  import co.elastic.clients.elasticsearch.ElasticsearchAsyncClient; import co.elastic.clients.elasticsearch.ElasticsearchClient; import co.elastic.clients.json.jackson.JacksonJsonpMapper; import co.elastic.clients.transport.rest_client.RestClientTransport; import lombok.Setter; import org.apache.http.HttpHost; import org.elasticsearch.client.RestClient; import org.springframework.boot.context.properties.ConfigurationProperties; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.util.StringUtils;  @ConfigurationProperties(prefix = "elasticsearch") //配置的前缀 @Configuration public class ClientConfig {      @Setter     private String hosts;      /**      * 解析配置的字符串，转为HttpHost对象数组      * @return      */     private HttpHost[] toHttpHost() {         if (!StringUtils.hasLength(hosts)) {             throw new RuntimeException("invalid elasticsearch configuration");         }          String[] hostArray = hosts.split(",");         HttpHost[] httpHosts = new HttpHost[hostArray.length];         HttpHost httpHost;         for (int i = 0; i < hostArray.length; i++) {             String[] strings = hostArray[i].split(":");             httpHost = new HttpHost(strings[0], Integer.parseInt(strings[1]), "http");             httpHosts[i] = httpHost;         }          return httpHosts;     }      @Bean     public ElasticsearchClient elasticsearchClient() {         HttpHost[] httpHosts = toHttpHost();         RestClient restClient = RestClient.builder(httpHosts).build();         RestClientTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());         return new ElasticsearchClient(transport);     }      @Bean     public ElasticsearchAsyncClient elasticsearchAsyncClient() {         HttpHost[] httpHosts = toHttpHost();         RestClient restClient = RestClient.builder(httpHosts).build();         RestClientTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());         return new ElasticsearchAsyncClient(transport);     } }

从上面的代码可以看出，配置类已经向Spring容器注册了ElasticsearchClient实例，后面的业务都可以使用此实例来操作ES

编码：服务类

本篇只是为了演示SpringBoot应用如何连接和操作ES，还不会深入ES操作的细节，因此只对索引做一些基本操作即可
先写一个接口IndexService.java，里面定义了多个索引操作的方法

package com.bolingcavalry.basic.service;  import co.elastic.clients.elasticsearch._types.mapping.TypeMapping; import co.elastic.clients.elasticsearch.indices.IndexSettings; import co.elastic.clients.util.ObjectBuilder;  import java.io.IOException; import java.util.function.Function;  public interface IndexService {      /**      * 新建指定名称的索引      * @param name      * @throws IOException      */     void addIndex(String name) throws IOException;      /**      * 检查指定名称的索引是否存在      * @param name      * @return      * @throws IOException      */     boolean indexExists(String name) throws IOException;      /**      * 删除指定索引      * @param name      * @throws IOException      */     void delIndex(String name) throws IOException;      /**      * 创建索引，指定setting和mapping      * @param name 索引名称      * @param settingFn 索引参数      * @param mappingFn 索引结构      * @throws IOException      */     void create(String name,                 Function<IndexSettings.Builder, ObjectBuilder<IndexSettings>> settingFn,                 Function<TypeMapping.Builder, ObjectBuilder<TypeMapping>> mappingFn) throws IOException; }

然后接口的实现，可见所有操作都是在调用ElasticsearchClient实例的API

package com.bolingcavalry.basic.service.impl;  import co.elastic.clients.elasticsearch.ElasticsearchClient; import co.elastic.clients.elasticsearch._types.mapping.TypeMapping; import co.elastic.clients.elasticsearch.indices.IndexSettings; import co.elastic.clients.util.ObjectBuilder; import com.bolingcavalry.basic.service.IndexService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.ApplicationContext; import org.springframework.stereotype.Service;  import java.io.IOException; import java.util.function.Function;  @Service public class IndexServiceImpl implements IndexService {      @Autowired     private ElasticsearchClient elasticsearchClient;      @Override     public void addIndex(String name) throws IOException {         ApplicationContext applicationContext;         elasticsearchClient.indices().create(c -> c.index(name));     }      @Override     public boolean indexExists(String name) throws IOException {         ApplicationContext a;         return elasticsearchClient.indices().exists(b -> b.index(name)).value();     }      @Override     public void delIndex(String name) throws IOException {         elasticsearchClient.indices().delete(c -> c.index(name));     }      @Override     public void create(String name,                        Function<IndexSettings.Builder, ObjectBuilder<IndexSettings>> settingFn,                        Function<TypeMapping.Builder, ObjectBuilder<TypeMapping>> mappingFn) throws IOException {        elasticsearchClient                .indices()                .create(c -> c                        .index(name)                        .settings(settingFn)                        .mappings(mappingFn)                );     } }

以上就是本篇的功能代码了，连接ES在其上进行索引相关操作

编码：单元测试

为了验证上述代码是否生效，接下来写一个单元测试类IndexServiceTest.java，可以重点关注createIndex方法，里面演示了Builder pattern构建参数的详细步骤

package com.bolingcavalry.basic.service;  import co.elastic.clients.elasticsearch._types.mapping.Property; import co.elastic.clients.elasticsearch._types.mapping.TypeMapping; import co.elastic.clients.elasticsearch.indices.IndexSettings; import co.elastic.clients.util.ObjectBuilder; import org.junit.jupiter.api.Assertions; import org.junit.jupiter.api.Test; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.boot.test.context.SpringBootTest;  import java.util.function.Function;  @SpringBootTest class IndexServiceTest {      @Autowired     IndexService indexService;      @Test     void addIndex() throws Exception {         String indexName = "test_index";          Assertions.assertFalse(indexService.indexExists(indexName));         indexService.addIndex(indexName);         Assertions.assertTrue(indexService.indexExists(indexName));         indexService.delIndex(indexName);         Assertions.assertFalse(indexService.indexExists(indexName));     }      @Test     void indexExists() throws Exception {         indexService.indexExists("a");     }      @Test     void createIndex() throws Exception {         // 索引名         String indexName = "product002";          // 构建setting时，builder用到的lambda         Function<IndexSettings.Builder, ObjectBuilder<IndexSettings>> settingFn = sBuilder -> sBuilder                 .index(iBuilder -> iBuilder                         // 三个分片                         .numberOfShards("3")                         // 一个副本                         .numberOfReplicas("1")                 );          // 新的索引有三个字段，每个字段都有自己的property，这里依次创建         Property keywordProperty = Property.of(pBuilder -> pBuilder.keyword(kBuilder -> kBuilder.ignoreAbove(256)));         Property textProperty = Property.of(pBuilder -> pBuilder.text(tBuilder -> tBuilder));         Property integerProperty = Property.of(pBuilder -> pBuilder.integer(iBuilder -> iBuilder));          // // 构建mapping时，builder用到的lambda         Function<TypeMapping.Builder, ObjectBuilder<TypeMapping>> mappingFn = mBuilder -> mBuilder                 .properties("name", keywordProperty)                 .properties("description", textProperty)                 .properties("price", integerProperty);          // 创建索引，并且指定了setting和mapping         indexService.create(indexName, settingFn, mappingFn);     } }

确保不做安全检查的ES集群运行正常，再执行单元测试，如下图，顺利通过，证明所有对ES的操作都符合预期

再用eshead观察product002索引的情况，如下图，三个分片，一个副本，与代码中设置的一致

至此最简单的连接和操作ES实战已经完成，希望本篇能给您一些参考，助您顺利完成基本操作

是不是线程安全的

官方回应：https://discuss.elastic.co/t/is-elasticsearch-client-is-thread-safe/151745
有人在问这个问题，es团队的成员Simon Willnauer的回答是：java的client肯定是线程安全的，golang的不清楚

对我来说，有他这话就够了，至于golang的嘛，在本文就不讨论了

源码下载

本篇实战的完整源码可在GitHub下载到，地址和链接信息如下表所示(https://github.com/zq2599/blog_demos)

名称	链接	备注
项目主页	https://github.com/zq2599/blog_demos	该项目在GitHub上的主页
git仓库地址(https)	https://github.com/zq2599/blog_demos.git	该项目源码的仓库地址，https协议
git仓库地址(ssh)	git@github.com:zq2599/blog_demos.git	该项目源码的仓库地址，ssh协议