一、Spring Cloud Alibaba依赖说明

使用Spring Cloud Alibaba与其它组件集成时一定要先看下依赖说明，下图是Spring Cloud Alibaba各组件对应的版本信息。

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下图是Spring Cloud Alibaba和Spring Cloud以及Spring Boot对应的适配版本关系。

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备注：具体版本说明请参考Spring Cloud Alibaba版本说明。

二、代码示例

1、父工程spring-cloud-alibaba-learning版本依赖信息

<groupId>com.universe</groupId>
<artifactId>spring-cloud-alibaba-learning</artifactId>
<packaging>pom</packaging>
<version>1.0.0-SNAPSHOT</version>

<modules>
        <module>spring-cloud-alibaba-seata-consumer</module>
        <module>spring-cloud-alibaba-seata-provider</module>
</modules>

<properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <spring.boot.version>2.3.12.RELEASE</spring.boot.version>
        <spring.cloud.version>Hoxton.SR12</spring.cloud.version>
        <spring.cloud.alibaba.version>2.2.6.RELEASE</spring.cloud.alibaba.version>
        <commons.lang3.version>3.12.0</commons.lang3.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-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>${commons.lang3.version}</version>
        </dependency>
</dependencies>

<dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-parent</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>

备注：
1、这里我们Spring Cloud Alibaba的版本使用的是2.2.6.RELEASE，Spring Cloud的版本是Hoxton.SR12，Spring Boot的版本用的是2.3.12.RELEASE。

2、Spring Cloud Alibaba版本2.2.6.RELEASE也是可以和上述依赖互相兼容的。

2、子工程spring-cloud-alibaba-seata-consumer服务消费者

(1) 版本依赖

<parent>
        <groupId>com.universe</groupId>
        <artifactId>spring-cloud-alibaba-learning</artifactId>
        <version>1.0.0-SNAPSHOT</version>
</parent>

<artifactId>spring-cloud-alibaba-seata-consumer</artifactId>

<properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <seata.spring.boot.version>1.4.2</seata.spring.boot.version>
        <mybatis.plus.boot.version>3.5.1</mybatis.plus.boot.version>
        <druid.spring.boot.version>1.2.8</druid.spring.boot.version>
        <mysql.connector.version>8.0.28</mysql.connector.version>
</properties>

<dependencies>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-dubbo</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql.connector.version}</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>${druid.spring.boot.version}</version>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>${mybatis.plus.boot.version}</version>
        </dependency>
    </dependencies>

(2) application.yml配置

# dubbo configuration
dubbo:
  registry:
    address: nacos://localhost:8848
  consumer:
    check: false
  scan:
    base-packages: com.universe.order.service.impl

spring:
  # datasource configuration
  datasource:
    druid:
      url: jdbc:mysql://localhost:3307/mall_order?serverTimeZone=UTC
      username: root
      password: root
      initial-size: 5
      max-active: 50
      max-wait: 3000
      test-on-borrow: false
      test-on-return: false
      min-idle: 10
      time-between-eviction-runs-millis: 60000
      min-evictable-idle-time-millis: 300000
  cloud:
    nacos:
      discovery:
        enabled: false # 禁用Nacos服务注册和发现

# mybatis-plus configuration
mybatis-plus:
  mapper-locations: classpath:mapper/*.xml
  configuration:
    map-underscore-to-camel-case: true
    call-setters-on-nulls: true

备注：
1、为什么配置dubbo.consumer.check为false呢？
如果服务启动时拉取不到服务提供者列表，启动时会报错。

2、为什么配置spring.cloud.nacos.discovery.enabled为false呢？
因为spring-cloud-starter-alibaba-nacos-discovery中有相关自动配置类会自动做服务注册和服务发现，导致服务启动报错。

(3) Dubbo服务引用

import com.baomidou.mybatisplus.core.conditions.Wrapper;
import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import com.universe.integral.MallIntegralService;
import com.universe.order.common.OrderStatusEnum;
import com.universe.order.mapper.MallOrderMapper;
import com.universe.order.pojo.ApiResponse;
import com.universe.order.pojo.domain.MallOrderDO;
import com.universe.order.service.MallOrderService;
import org.apache.dubbo.config.annotation.DubboReference;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

/**
 * @author 刘亚楼
 * @date 2022/4/11
 */
@Service
public class MallOrderServiceImpl implements MallOrderService {

    @Autowired
    private MallOrderMapper mallOrderMapper;

    @DubboReference(timeout = 3000)
    private MallIntegralService mallIntegralService;

    @Override
    public ApiResponse<Void> finishOrder(String orderNo, Long userId) {
        Wrapper<MallOrderDO> wrapper = Wrappers.<MallOrderDO>lambdaQuery().eq(MallOrderDO::getOrderNo, orderNo);
        MallOrderDO mallOrderDO = mallOrderMapper.selectOne(wrapper);
        if (mallOrderDO == null) {
            return ApiResponse.error("B0001");
        }

        mallOrderDO.setOrderStatus(OrderStatusEnum.FINISHED.getStatus());
        mallOrderDO.setUpdateTime(System.currentTimeMillis());
        Wrapper<MallOrderDO> updateWrapper = Wrappers.<MallOrderDO>lambdaUpdate().eq(MallOrderDO::getOrderNo, orderNo);
        mallOrderMapper.update(mallOrderDO, updateWrapper);


        return null;
    }
}

备注：Dubbo==2.7.8==版本服务引入注解由@Reference变成了@DubboReference。

(4) 启动类

@MapperScan(basePackages = "com.universe.integral.mapper")
@SpringBootApplication
public class Application {

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

}

3、子工程spring-cloud-alibaba-seata-provider服务提供者

(1) 版本依赖

<parent>
        <artifactId>spring-cloud-alibaba-learning</artifactId>
        <groupId>com.universe</groupId>
        <version>1.0.0-SNAPSHOT</version>
</parent>

    <artifactId>spring-cloud-alibaba-seata-provider</artifactId>

<properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <seata.spring.boot.version>1.4.2</seata.spring.boot.version>
        <mybatis.plus.boot.version>3.5.1</mybatis.plus.boot.version>
        <druid.spring.boot.version>1.2.8</druid.spring.boot.version>
        <mysql.connector.version>8.0.28</mysql.connector.version>
</properties>

<dependencies>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-dubbo</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql.connector.version}</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>${druid.spring.boot.version}</version>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>${mybatis.plus.boot.version}</version>
        </dependency>
    </dependencies>

(2) application.yml配置

# dubbo configuration
dubbo:
  registry:
    address: nacos://localhost:8848
  protocol:
    port: 20881
    name: dubbo # 这配置不能丢，丢了会报错
  scan:
    base-packages: com.universe.integral.service.impl

spring:
  # datasource configuration
  datasource:
    druid:
      url: jdbc:mysql://localhost:3307/mall_integral?serverTimeZone=UTC
      username: root
      password: root
      initial-size: 5
      max-active: 50
      max-wait: 3000
      test-on-borrow: false
      test-on-return: false
      min-idle: 10
      time-between-eviction-runs-millis: 60000
      min-evictable-idle-time-millis: 300000
  cloud:
    nacos:
      discovery:
        enabled: false # 禁用Nacos服务自动发现

# mybatis-plus configuration
mybatis-plus:
  mapper-locations: classpath:mapper/*.xml
  configuration:
    map-underscore-to-camel-case: true
    call-setters-on-nulls: true

备注： 对于服务提供者，这里有个小坑，就是dubbo.protocol.name这项配置不能丢，丢了服务启动时会出现协议校验出错，如下图：
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(3) 服务实现类

package com.universe.integral.service.impl;

import com.universe.integral.mapper.UserIntegralMapper;
import com.universe.integral.pojo.ApiResponse;
import com.universe.integral.pojo.request.AddUserIntegralRequest;
import com.universe.integral.service.MallIntegralService;
import org.apache.dubbo.config.annotation.DubboService;
import org.springframework.beans.factory.annotation.Autowired;

/**
 * @author 刘亚楼
 * @date 2022/4/11
 */
@DubboService
public class MallIntegralServiceImpl implements MallIntegralService {

    @Autowired
    private UserIntegralMapper userIntegralMapper;

    @Override
    public ApiResponse<AddUserIntegralRequest> dispatchUserIntegral(AddUserIntegralRequest request) {
        return null;
    }
}

备注：为了更好和Spring原生注解@Service区分，Dubbo==2.7.8==版本标识服务提供者注解变成了@DubboService。

(4) 启动类

@MapperScan(basePackages = "com.universe.integral.mapper")
@SpringBootApplication
public class Application {

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

三、启动服务&查看Nacos控制台

可以看到服务提供者和服务消费者已经成功注册到了Nacos上，说明Dubbo和Nacos整合是成功的。

image.png

四、总结

1、Spring Cloud Alibaba已经提供了相关Dubbo的依赖，在==Github上==的版本依赖关系表中已经给出了相应的适配组件版本。

2、spring-cloud-starter-dubbo依赖会引入dubbo-spring-boot-starter依赖，这里我们使用的dubbo版本是==2.7.8==。

3、注意禁用spring-cloud-starter-alibaba-nacos-discovery的服务自动注册和发现，或者如果我们不禁用，可以通过@SpringBootApplication注解排除NacosServiceRegistryAutoConfiguration和NacosDiscoveryClientConfiguration的自动配置，如下：

image.png