Spring Cloud 整合 Dubbo

provider 端配置

引入依赖：

  1. <dependency>
  2.     <groupId>com.alibaba.cloud</groupId>
  3.     <artifactId>spring-cloud-starter-dubbo</artifactId>
  4. </dependency>
  6. <dependency>
  7.     <groupId>com.alibaba.cloud</groupId>
  8.     <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
  9. </dependency>

application.yml

dubbo:
  scan:
    # 指定 Dubbo 服务实现类的扫描基准包
    base-packages: com.zrk.mall.user.service
#  application:
#    name: ${spring.application.name}
  protocol:
    # dubbo 协议
    name: dubbo
    # dubbo 协议端口（ -1 表示自增端口，从 20880 开始）
    port: -1
#  registry:
#    #挂载到 Spring Cloud 注册中心  高版本可选
#    address: spring-cloud://127.0.0.1:8848

spring:
  application:
    name: spring-cloud-dubbo-provider-user
  main:
    # Spring Boot2.1及更高的版本需要设定
    allow-bean-definition-overriding: true
  cloud:
    nacos:
      # Nacos 服务发现与注册配置
      discovery:
        server-addr: 127.0.0.1:8848

服务实现类上配置@DubboService暴露服务：

@DubboService
public class UserServiceImpl implements UserService {

   @Autowired
   private UserMapper userMapper;

   @Override
   public List<User> list() {
      return userMapper.list();
   }

   @Override
   public User getById(Integer id) {
      return userMapper.getById(id);
   }
}

consumer 端配置

引入依赖：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<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>

application.yml

dubbo:
  cloud:
    # 指定需要订阅的服务提供方，默认值*，会订阅所有服务，不建议使用
    subscribed-services: spring-cloud-dubbo-provider-user
#  application:
#    name: ${spring.application.name}
  protocol:
    # dubbo 协议
    name: dubbo
    # dubbo 协议端口（ -1 表示自增端口，从 20880 开始）
    port: -1
#  registry:
#    #挂载到 Spring Cloud 注册中心  高版本可选
#    address: spring-cloud://127.0.0.1:8848

spring:
  application:
    name: spring-cloud-dubbo-consumer-user
  main:
    # Spring Boot2.1及更高的版本需要设定
    allow-bean-definition-overriding: true
  cloud:
    nacos:
      # Nacos 服务发现与注册配置
      discovery:
        server-addr: 127.0.0.1:8848

服务消费方通过@DubboReference引入服务：

@RestController
@RequestMapping("/user")
public class UserConstroller {

    @DubboReference
    private UserService userService;

    @RequestMapping("/info/{id}")
    public User info(@PathVariable("id") Integer id){
        return userService.getById(id);
    }

    @RequestMapping("/list")
    public List<User> list(){
        return userService.list();
    }
}

从 OpenFeign 迁移到 Dubbo

Dubbo Spring Cloud 提供了方案，即@DubboTransported注解，支持在类、方法、属性上使用；能够帮助服务消费端的 Spring Cloud Open Feign 接口以及@LoadBalanced RestTemplate Bean底层走 Dubbo 调用（可切换 Dubbo 支持的协议），而服务提供方则只需在原有@RestController类上追加 Dubbo@Service注解（需要抽取接口）即可；换言之，在不调整 Feign 接口以及 RestTemplate URL 的前提下，实现无缝迁移

修改服务提供者：

@DubboService
@Slf4j
@RestController
@RequestMapping("/user")
public class UserServiceImpl implements UserService {

   @Autowired
   private UserMapper userMapper;

   @Override
   @RequestMapping("/list")
   public List<User> list() {
      log.info("查询user列表");
      return userMapper.list();
   }

   @Override
   @RequestMapping("/getById/{id}")
   public User getById(@PathVariable("id") Integer id) {
      return userMapper.getById(id);
   }
}

服务消费端引入依赖：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<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>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>

Feign 的实现，启动类上添加@EnableFeignClients：

@SpringBootApplication
@EnableFeignClients
public class SpringCloudDubboConsumerUserFeignApplication {

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

Feign 接口添加@DubboTransported注解：

@FeignClient(value = "spring-cloud-dubbo-provider-user-feign",path = "/user")
@DubboTransported(protocol = "dubbo")
public interface UserDubboFeignService {

    @RequestMapping("/list")
    public List<User> list();

    @RequestMapping("/getById/{id}")
    public User getById(@PathVariable("id") Integer id);
}

@FeignClient(value = "spring-cloud-dubbo-provider-user-feign",path = "/user")
public interface UserFeignService {

    @RequestMapping("/list")
    public List<User> list();


    @RequestMapping("/getById/{id}")
    public User getById(@PathVariable("id") Integer id);
}

调用对象添加@DubboTransported注解：

@RestController
@RequestMapping("/user")
public class UserConstroller {

    @DubboReference
    private UserService userService;

    @RequestMapping("/info/{id}")
    public User info(@PathVariable("id") Integer id){
        return userService.getById(id);
    }

    @Autowired
    @DubboTransported
    private UserFeignService userFeignService;

    @RequestMapping("/list")
    public List<User> list(){
        return userFeignService.list();
    }

    @Autowired
    private UserDubboFeignService userDubboFeignService;

    @RequestMapping("/list2")
    public List<User> list2(){

        return userDubboFeignService.list();
    }

    @Autowired
    private RestTemplate restTemplate;

    @Bean
    @LoadBalanced
    @DubboTransported
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }

    @RequestMapping("/list3")
    public List<User> list3(){
        String url = "http://spring-cloud-dubbo-provider-user-feign/user/list";
        return restTemplate.getForObject(url, List.class);
    }
}