2.1.1版本Spring-cloud + Dubbo + Nacos初试

桃扇骨 2023-05-22 04:52 31阅读 0赞

# 一、主要组件 #

*  Nacos 服务注册与发现、配置中心
 *  Dubbo 分布式服务框架

版本选择：2.1.1

# 二、项目架构 #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21lbmdsaW5qaWU_size_16_color_FFFFFF_t_70][]

如图：

*  common-api : 存放 Dubbo 服务接口和模型定义
 *  provider : 服务提供者
 *  consumer : 服务消费者

# 三、项目搭建 #

1、创建父工程spring-cloud-alibaba-example

1.  新建项目 file -> new project ..创建一个springboot项目
2.  删除多余文件，只留下pom文件
3.  修改pom文件，进行依赖版本管理

<?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.mlj</groupId>
        <artifactId>snapup</artifactId>
        <packaging>pom</packaging>
        <version>0.0.1-SNAPSHOT</version>
        <name>snapup</name>
    
        <modules>
            <module>consumer</module>
            <module>provider</module>
            <module>common-api</module>
        </modules>
    
        <properties>
            <java.version>1.8</java.version>
            <spring-boot.version>2.1.1.RELEASE</spring-boot.version>
            <spring-cloud.version>Greenwich.SR5</spring-cloud.version>
            <spring-cloud-alibaba.version>2.1.1.RELEASE</spring-cloud-alibaba.version>
            <maven.compiler.source>1.8</maven.compiler.source>
            <maven.compiler.target>1.8</maven.compiler.target>
        </properties>
    
        <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>
                
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-dependencies</artifactId>
                    <version>${spring-cloud.version}</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
                
                <dependency>
                    <groupId>com.alibaba.cloud</groupId>
                    <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                    <version>${spring-cloud-alibaba.version}</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
            </dependencies>
        </dependencyManagement>
    
        <dependencies>
            
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <scope>provided</scope>
            </dependency>
        </dependencies>
    
        <build>
            <finalName>${project.name}</finalName>
            <resources>
                <resource>
                    <directory>src/main/resources</directory>
                    <filtering>true</filtering>
                </resource>
            </resources>
            <pluginManagement>
                <plugins>
                    <plugin>
                        <groupId>org.springframework.boot</groupId>
                        <artifactId>spring-boot-maven-plugin</artifactId>
                        <version>${spring-boot.version}</version>
                    </plugin>
                </plugins>
            </pluginManagement>
            <plugins>
                <plugin>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.8.0</version>
                    <configuration>
                        <target>${maven.compiler.target}</target>
                        <source>${maven.compiler.source}</source>
                        <encoding>UTF-8</encoding>
                        <skip>true</skip>
                    </configuration>
                </plugin>
            </plugins>
        </build>
    
        <repositories>
            <repository>
                <id>spring-milestones</id>
                <name>Spring Milestones</name>
                <url>https://repo.spring.io/libs-milestone</url>
                <snapshots>
                    <enabled>false</enabled>
                </snapshots>
            </repository>
        </repositories>
    </project>

## 2、创建common-api ##

存放 Dubbo 服务接口和模型定义

1.  创建module，普通maven项目
2.  创建接口和dto

SnaPupService:

public interface SnaPupService {
    
        /**
         * 接口
         *
         * @param s
         * @return
         */
        Result get(String s);
    }

Result:

@Data
    @NoArgsConstructor
    @AllArgsConstructor
    public class Result implements Serializable {
        private String data;
    }

pom:

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21lbmdsaW5qaWU_size_16_color_FFFFFF_t_70 1][]

# 3、nacos创建相关配置  #

需要提前下载安装nacos，官方文档：[https://nacos.io/zh-cn/docs/quick-start.html][https_nacos.io_zh-cn_docs_quick-start.html]

1.   创建命名空间

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21lbmdsaW5qaWU_size_16_color_FFFFFF_t_70 2][]

2.添加provider和consumer配置

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21lbmdsaW5qaWU_size_16_color_FFFFFF_t_70 3][]

## 4、创建服务提供者 provider ##

1.  创建module 选择创建springboot项目
2.  修改pom，引入相关依赖，如下
3.  修改配置文件为bootstrap.yml yml格式，如下
4.  启动类添加@EnableDubbo注解，开启注解Dubbo功能；添加@EnableDiscoveryClient注解，进行服务注册
5.  创建SnaPupServiceImpl实现common-api的接口，完善接口功能，SnaPupServiceImpl类上需要@Service注解（org.apache.dubbo.config.annotation.Service）暴露服务

bootstrap.yml：

spring:
      application:
        name: @artifactId@
      cloud:
        nacos:
    # nacos地址
          server-addr: ****
    #服务注册与发现
          discovery:
    # group和命名空间
            group: SNAPUP_GROUP
            namespace: 725d62dc-11f8-451d-ac7e-04427536de08
    #配置中心
          config:
            group: SNAPUP_GROUP
            namespace: 725d62dc-11f8-451d-ac7e-04427536de08
            file-extension: yaml
            enable-remote-sync-config: true

## 5、创建服务消费者 consumer ##

1.  创建module 选择创建springboot项目，如provider
2.  修改pom，引入相关依赖，如provider
3.  修改配置文件为bootstrap.yml yml格式，如provider
4.  启动类添加@EnableDubbo注解，进行dubbo包扫描；添加@EnableDiscoveryClient注解，进行服务注册，如provider
5.  创建SnaPupController接口，使用@Reference注解注入common-api的接口 来引用服务，进行调用。@RefreshScope注解会实时刷新$\{user.name\}配置信息

@RestController
    @RequestMapping("/snaPup")
    @RefreshScope
    public class SnaPupController {
    
        @Reference
        private SnaPupService snaPupService;
    
        @Value("${user.name}")
        private String name;
    
        @GetMapping("/get")
        public Result get() {
            return snaPupService.get(name);
        }
    }

#   三、测试组件可用性 #

1.  依此启动provider、consumer服务
2.  观察nacos客户端 ，可以看到刚启动的两个服务
3.  请求接口[http://localhost:8003/snaPup/get][http_localhost_8003_snaPup_get]，访问成功

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21lbmdsaW5qaWU_size_16_color_FFFFFF_t_70 4][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21lbmdsaW5qaWU_size_16_color_FFFFFF_t_70 5][]

# 四、问题与解决 #

1、警告信息：  
Current application will subscribe all services(size:2) in registry, a lot of memory and CPU cycles may be used, thus it's strongly recommend you using the externalized property 'dubbo.cloud.subscribed-services' to specify the services

解决：dubbo.cloud.subscribed-services : provider 用于服务消费方订阅服务提供方的应用名称的列表，若需订阅多应用，使用 "," 分割。不推荐使用默认值为 "\*"，它将订阅所有应用，默认订阅所有应用。

2、修改配置不会自动刷新

解决：通过 Spring Cloud 原生注解 `@RefreshScope` 实现配置自动更新，官方文档有说明。[https://nacos.io/zh-cn/docs/quick-start-spring-cloud.html][https_nacos.io_zh-cn_docs_quick-start-spring-cloud.html]

# 五、相关注解总结 #

@org.apache.dubbo.config.annotation.Service 暴露服务
    @Reference 引用服务
    @EnableDubbo 开启注解Dubbo功能
    @EnableDiscoveryClient 开启服务注册发现功能
    @RefreshScope 实现配置自动更新

# 六、参考文档 #

1.  nacos官方文档 [https://nacos.io/zh-cn/docs/quick-start-spring-cloud.html][https_nacos.io_zh-cn_docs_quick-start-spring-cloud.html]
2.  dubbo官方文档 [http://dubbo.apache.org/en-us/docs/user/quick-start.html][http_dubbo.apache.org_en-us_docs_user_quick-start.html]
3.  dubbo相关 [https://segmentfault.com/a/1190000018991721][https_segmentfault.com_a_1190000018991721]
4.  dubbo相关 [https://www.jianshu.com/p/3090d63e9cb3][https_www.jianshu.com_p_3090d63e9cb3]

### 完整代码见github: [https://github.com/menglinjie/spring-cloud-alibaba-example][https_github.com_menglinjie_spring-cloud-alibaba-example] ###

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21lbmdsaW5qaWU_size_16_color_FFFFFF_t_70]: /images/20230521/30d4010ba30847dbb5708ea30dfa128d.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21lbmdsaW5qaWU_size_16_color_FFFFFF_t_70 1]: /images/20230521/581d2cee228249ea9356b204f5406e3f.png
[https_nacos.io_zh-cn_docs_quick-start.html]: https://nacos.io/zh-cn/docs/quick-start.html
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21lbmdsaW5qaWU_size_16_color_FFFFFF_t_70 2]: /images/20230521/ffa6bb6d73b6451cb685fb381c2cae74.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21lbmdsaW5qaWU_size_16_color_FFFFFF_t_70 3]: /images/20230521/c209c0f6f6504356adbe753d72ebfb66.png
[http_localhost_8003_snaPup_get]: http://localhost:8003/snaPup/get
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21lbmdsaW5qaWU_size_16_color_FFFFFF_t_70 4]: /images/20230521/d06670c6293f4800a9fed921fcdc51fa.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21lbmdsaW5qaWU_size_16_color_FFFFFF_t_70 5]: /images/20230521/73a075e288544b99a2da0531312ad0ad.png
[https_nacos.io_zh-cn_docs_quick-start-spring-cloud.html]: https://nacos.io/zh-cn/docs/quick-start-spring-cloud.html
[http_dubbo.apache.org_en-us_docs_user_quick-start.html]: http://dubbo.apache.org/en-us/docs/user/quick-start.html
[https_segmentfault.com_a_1190000018991721]: https://segmentfault.com/a/1190000018991721
[https_www.jianshu.com_p_3090d63e9cb3]: https://www.jianshu.com/p/3090d63e9cb3
[https_github.com_menglinjie_spring-cloud-alibaba-example]: https://github.com/menglinjie/spring-cloud-alibaba-example