新鲜速递：Spring Cloud Alibaba环境在Spring Boot 3时代的快速搭建

Love The Way You Lie 2024-02-23 01:12 18阅读 0赞

## 了解 ##

首先，Spring Cloud Alibaba使用的是Nacos作为服务注册和服务发现的中间件。  
![在这里插入图片描述][2eeab4178f954d75bdd7ae43c67dbb05.png]  
能力在提供者那里，而消费者只需知道提供者提供哪些服务，而无需关心提供者在哪里，实际调用过程如下图  
![在这里插入图片描述][0ee1ec7e59be4aea845c91c7efe22bfd.png]

## 准备工作 ##

1、需要下载并安装Nacos最新版  
下载安装过程略，如果是单机启动请建立一个批处理放在解压后的bin目录里，命令内容就一行：startup.cmd -m standalone  
用单机模式启动Nacos，如果你是Linux系统，请改成.sh并加上bash头  
2、启动nacos，默认用户名密码均为nacos，端口号为8848，但同时要注意，如果你是docker部署，因为有gRPC协议，还需要放行9848端口。  
3、Nacos作为一个配置中心，还需要加上我们应用的配置，可以少写很多配置。  
![在这里插入图片描述][a88d9c1a98d04d35acf8e5aa6eb72b8f.png]

## 配置中心添加配置文件 ##

点击加号，添加这三个配置文件，**配置格式都为YAML**  
![在这里插入图片描述][1768ad765450489892ad83be16f16277.png]  
application-dev.yml内容：

feign:
      sentinel:
        enabled: true
      okhttp:
        enabled: true
      httpclient:
        enabled: false
      client:
        config:
          default:
            connectTimeout: 10000
            readTimeout: 10000
      compression:
        request:
          enabled: true
        response:
          enabled: true
    
    management:
      endpoints:
        web:
          exposure:
            include: '*'

provider-dev.yml和consumer-dev.yml内容：

spring:

## 项目搭建 ##

先随便建立一个空白Maven项目，只要pom.xml文件，src目录是不需要的。然后把pom.xml改成如下：

<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/maven-v4_0_0.xsd">
        <modelVersion>4.0.0</modelVersion>
        <groupId>com.demo</groupId>
        <artifactId>demo</artifactId>
        <version>1.0-SNAPSHOT</version>
    
        <modules>
            <module>provider</module>
            <module>consumer</module>
            <module>api</module>
        </modules>
    
        <properties>
            <java.version>17</java.version>
            <maven.compiler.source>17</maven.compiler.source>
            <maven.compiler.target>17</maven.compiler.target>
        </properties>
    
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-dependencies</artifactId>
                    <version>3.1.4</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-dependencies</artifactId>
                    <version>2022.0.4</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
                <dependency>
                    <groupId>com.alibaba.cloud</groupId>
                    <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                    <version>2022.0.0.0</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
    
                <dependency>
                    <groupId>com.demo</groupId>
                    <artifactId>consumer</artifactId>
                    <version>0.0.1-SNAPSHOT</version>
                </dependency>
    
                <dependency>
                    <groupId>com.demo</groupId>
                    <artifactId>api</artifactId>
                    <version>0.0.1-SNAPSHOT</version>
                </dependency>
    
                <dependency>
                    <groupId>com.demo</groupId>
                    <artifactId>provider</artifactId>
                    <version>0.0.1-SNAPSHOT</version>
                </dependency>
            </dependencies>
        </dependencyManagement>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
            </dependency>
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <optional>true</optional>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-bootstrap</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-openfeign</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-loadbalancer</artifactId>
            </dependency>
        </dependencies>
    
        <repositories>
            <repository>
                <id>public</id>
                <name>aliyun nexus</name>
                <url>https://maven.aliyun.com/repository/public</url>
                <releases>
                    <enabled>true</enabled>
                </releases>
            </repository>
        </repositories>
    
        <pluginRepositories>
            <pluginRepository>
                <id>public</id>
                <name>aliyun nexus</name>
                <url>https://maven.aliyun.com/repository/public</url>
                <releases>
                    <enabled>true</enabled>
                </releases>
                <snapshots>
                    <enabled>false</enabled>
                </snapshots>
            </pluginRepository>
        </pluginRepositories>
    
        <packaging>pom</packaging>
    
        <build>
            <pluginManagement>
                <plugins>
                    <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>
                        <version>3.1.4</version>
                        <executions>
                            <execution>
                                <goals>
                                    <goal>repackage</goal>
                                </goals>
                            </execution>
                        </executions>
                    </plugin>
                </plugins>
            </pluginManagement>
        </build>
    </project>

然后搭建三个子项目，api、provider、consumer，分别代表API库、提供者和消费者  
![在这里插入图片描述][785f127a6351489bbd0502b286ff7ac6.png]  
目录结构应当是，api、provider、consumer目录和pom.xml文件平级

## 提供者编写 ##

提供者的pom.xml，在provider目录下。要注意和主项目的dependencyManagement中provider的声明保持一致。

<?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>
        <parent>
            <groupId>com.demo</groupId>
            <artifactId>demo</artifactId>
            <version>1.0-SNAPSHOT</version>
        </parent>
    
        <artifactId>provider</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>provider</name>
    
        <dependencies>
    
        </dependencies>
    </project>

编写启动类，关键点是添加`@EnableFeignClients(basePackages = "com.demo")`注解

package com.demo.provider;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.openfeign.EnableFeignClients;
    
    @EnableFeignClients(basePackages = "com.demo")
    @SpringBootApplication
    public class ProviderApplication {
        
    
        public static void main(String[] args) {
        
            SpringApplication.run(ProviderApplication.class, args);
        }
    
    }

随便写一个**非常正常、平平无奇**的Controller：

package com.demo.provider;
    
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    @RequestMapping("/")
    public class ProviderController {
        
        @RequestMapping("sayHello")
        public String sayHello(String name){
        
            return "你好，"+name;
        }
    }

然后在resources目录里建立一个bootstrap.yml文件

server:
      port: 9001
    
    spring:
      application:
        name: provider
      profiles:
        active: dev
      cloud:
        nacos:
          discovery:
            server-addr: localhost:8848
          config:
            server-addr: localhost:8848
            file-extension: yml
            shared-configs:
              - application-${
        spring.profiles.active}.${
        spring.cloud.nacos.config.file-extension}

注意，把localhost替换成你的Nacos服务器地址

## API编写 ##

API的pom.xml如下（除了name和artifactId不一样，其他都和提供者一样）。

<?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>
        <parent>
            <groupId>com.demo</groupId>
            <artifactId>demo</artifactId>
            <version>1.0-SNAPSHOT</version>
        </parent>
    
        <artifactId>api</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>api</name>
    
        <dependencies>
    
        </dependencies>
    
    </project>

关键位置来了，API类是这么写的，这里用了OpenFeign技术

package com.demo.api;
    
    import org.springframework.cloud.openfeign.FeignClient;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    
    @FeignClient(contextId = "providerMicroService", value = "provider", fallbackFactory = ProviderMicroServiceFallBackFactory.class)
    public interface ProviderMicroService
    {
        
        @GetMapping("/sayHello")
        String sayHello(@RequestParam("name") String name);
    }

这里`contextId`指的是上下文ID，类名的小写驼峰即可。`value`表示你要调哪个服务，`fallbackFactory`是指当服务无法访问或抛出异常时服务降级类是哪个。剩下的都很好理解，注意Get Mapping指的就是上面提供者Controller的类和方法的RequestMapping注解拼起来的地址。然后每一个参数都要加上@RequestParam注解并写上叫什么名（不加就会报错）。  
然后我们写服务降级类，如果你不想降级，也可以不写：

package com.demo.api;
    
    import org.springframework.cloud.openfeign.FallbackFactory;
    import org.springframework.stereotype.Component;
    @Component
    public class ProviderMicroServiceFallBackFactory implements FallbackFactory<ProviderMicroService>
    {
        
        @Override
        public ProviderMicroService create(Throwable throwable){
        
            return new ProviderMicroService() {
        
                @Override
                public String sayHello(String name) {
        
                    return "服务访问失败";
                }
            };
        }
    }

## 消费者编写 ##

consumer项目的pom.xml如下，注意这里多了一个对api的引用。

<?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>
        <parent>
            <groupId>com.demo</groupId>
            <artifactId>demo</artifactId>
            <version>1.0-SNAPSHOT</version>
        </parent>
    
        <artifactId>consumer</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>consumer</name>
    
        <dependencies>
            <dependency>
                <groupId>com.demo</groupId>
                <artifactId>api</artifactId>
            </dependency>
        </dependencies>
    
    </project>

然后编写启动类，同样，关键是`@EnableFeignClients(basePackages = "com.demo")`这一行

package com.demo.consumer;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.openfeign.EnableFeignClients;
    
    @EnableFeignClients(basePackages = "com.demo")
    @SpringBootApplication
    public class ConsumerApplication {
        
    
        public static void main(String[] args) {
        
            SpringApplication.run(ConsumerApplication.class, args);
        }
    
    }

最后我们编写消费者的Controller，这里的重点是MicroService是要用`@Resource`引入，不建议使用@Autowired：

package com.demo.consumer;
    
    import com.demo.api.ProviderMicroService;
    import jakarta.annotation.Resource;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    @RequestMapping("/")
    public class ConsumerController {
        
        @Resource
        ProviderMicroService providerMicroService;
        @RequestMapping("consumer")
        public String consumer(String name){
        
            return providerMicroService.sayHello(name);
        }
    }

我们编写一个bootstrap.yml文件，用来启动时连接到nacos，只有name和port和provider不一样，其余的配置都是通过配置中心从nacos拉consumer-dev.yml来整合的。

server:
      port: 9000
    
    spring:
      application:
        name: consumer
      profiles:
        active: dev
      cloud:
        nacos:
          discovery:
            server-addr: localhost:8848
          config:
            server-addr: localhost:8848
            file-extension: yml
            shared-configs:
              - application-${
        spring.profiles.active}.${
        spring.cloud.nacos.config.file-extension}

## 最后一步：测试 ##

此时我们打开consumer的Controller地址，给一个name参数，即可看到效果。这说明服务已经正常运行。  
![在这里插入图片描述][fec157ea7dd849ac93aa4bc06d1cd8b0.png]  
然后在nacos里可以看到服务的状态，说明微服务架构运行正常：  
![在这里插入图片描述][c0820b8c123f4bc892e0d7244c8e7c3a.png]

[2eeab4178f954d75bdd7ae43c67dbb05.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/23/77b63a62b6ef484e9b9ddfe44dd55f78.png
[0ee1ec7e59be4aea845c91c7efe22bfd.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/23/1b17d31639f74cd294c829ee9328c1ab.png
[a88d9c1a98d04d35acf8e5aa6eb72b8f.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/23/518f505ef9eb4699af4b4e1d1ff3211a.png
[1768ad765450489892ad83be16f16277.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/23/c6e9ccc815ad414da46e981c898da4c2.png
[785f127a6351489bbd0502b286ff7ac6.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/23/adad723494614d80a6b48f84317abea2.png
[fec157ea7dd849ac93aa4bc06d1cd8b0.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/23/165643a3bdc8433abb45ee11c5852066.png
[c0820b8c123f4bc892e0d7244c8e7c3a.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/23/c43475605e2c4635a386987a43bff015.png