环境 springboot + springcloud

Nacos注册中心服务端

下载windows版或Linux版：https://nacos.io/zh-cn
目录结构：

配置文件./config/application.properties

启动文件./bin/startup.cmd：

cmd命令启动单机服务startup.cmd -m standalone

 

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父工程依赖

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-alibaba-dependencies</artifactId>
    <version>2.2.6.RELEASE</version>
    <type>pom</type>
    <scope>import</scope>
</dependency>

 

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Service提供者

pom.xml

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>

application.yml

spring:
  application:
    name: userservice
spring:
  cloud:
    nacos:
      server-addr: http://localhost:8848

 

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consumer消费者 (消费者也可以作为提供者身份出现)

pom.xml

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>

application.yml

spring:
  application:
    name: orderservice
spring:
  cloud:
    nacos:
      server-addr: http://localhost:8848
      discovery:
        cluster-name: SZ  # 集群名称		

OrderApplication 配置RestTemplate的Bean加入到Spring容器中

@MapperScan("cn.xxx.order.mapper")
@SpringBootApplication
public class OrderApplication {

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

    @Bean
    @LoadBalanced # 负责均衡 和 做拉取服务
    public RestTemplate getRestTemplate() {
        return new RestTemplate();
    }
}

OrderService 利用RestTemplate调用 UserService接口

@Service
public class OrderService {

    @Autowired
    private OrderMapper orderMapper;
    @Autowired
    private RestTemplate restTemplate;

    public Order queryOrderById(Long orderId) {
        Order order = orderMapper.findById(orderId);

		// restTemplate.getForObject(请求地址, 返回值类型);
        String url = "http://userservice/user/" + order.getUserId(); // userservice是提供者的spring.application.name
        User user = restTemplate.getForObject(url, User.class);
        order.setUser(user);
        
        return order;
    }
}

 

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同集群优先的负载均衡（NacosRule）：默认的ZoneAvoidanceRule并不能实现根据同集群优先来实现负载均衡。

application.xml

userservice:
  ribbon:
    NFLoadBalancerRuleClassName: com.alibaba.cloud.nacos.ribbon.NacosRule # Nacos负载均衡规则