Eureka 注册中心的使用

环境 springboot + springcloud

Eureka-Server注册中心服务端

pom.xml导入依赖

<dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-netflix-eureka-server</artifactId><version>2.2.7.RELEASE</version> <!-- 一般在父工程中就配置了 -->
</dependency>

aplication.yml配置

server:port: 10086
spring:application:name: eurekaserver   # 服务名，需要配置
eureka:client:service-url:defaultZone: http://127.0.0.1:10086/eureka

EurekaServerApplication.java启动类配置

@SpringBootApplication
@EnableEurekaServer  // 开启eureka的注册中心功能
public class EurekaServerApplication {public static void main(String[] args) {SpringApplication.run(EurekaServerApplication.class, args);}
}

 

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Service提供者

pom.xml

<dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-netflix-eureka-client</artifactId><version>2.2.7.RELEASE</version> 	<!-- 一般在父工程中就配置了 -->
</dependency>

application.yml

spring:application:name: userservice
eureka:client:service-url:defaultZone: http://127.0.0.1:10086/eureka

 

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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>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-netflix-eureka-client</artifactId><version>2.2.7.RELEASE</version> 	<!-- 一般在父工程中就配置了 -->
</dependency>

application.yml

spring:application:name: orderservice
eureka:client:service-url:defaultZone: http://127.0.0.1:10086/eureka

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 {@Autowiredprivate OrderMapper orderMapper;@Autowiredprivate 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.nameUser user = restTemplate.getForObject(url, User.class);order.setUser(user);return order;}
}

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Ribbon负载均衡 (service配置)

方式1：重写IRule接口的实现Bean

@Bean
public IRule randomRule() {return new RandomRule();
}

方式2：配置文件指定

application.xml

userservice: # 给某个微服务配置负载均衡规则，这里是userservice服务ribbon:NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RandomRule # 负载均衡规则 # 当第一次访问时才会拉取服务再做缓存

饥饿加载配置：容器加载完毕后就拉取服务做缓存

ribbon:eager-load:enabled: trueclients:- userservice		# 指定一启动就加载的服务，可以配置多个-  xxxservice1