SpringCloud之 Ribbon

UserController

@RestController
public class UserController {
  @Autowired
  private UserRepository userRepository;
  @Autowired
  private Registration registration;

  @GetMapping("/{id}")
  public User findById(@PathVariable Long id) {
    User findOne = userRepository.findOne(id);
    return findOne;
  }

  @GetMapping("/getIpAndPort")
  public String findById() {
      return registration.getHost() + ":" + registration.getPort();
  }
}

user服务提供者,配置

server:
  port: 8001
spring:
  application:
    name: microservice-provider-user
  jpa:
    generate-ddl: false
    show-sql: true
    hibernate:
      ddl-auto: none
  datasource:                           # 指定数据源
    platform: h2                        # 指定数据源类型
    schema: classpath:schema.sql        # 指定h2数据库的建表脚本
    data: classpath:data.sql            # 指定h2数据库的数据脚本
logging:           # 配置日志级别，让hibernate打印出执行的SQL
  level:
    root: INFO
    org.hibernate: INFO
    org.hibernate.type.descriptor.sql.BasicBinder: TRACE
    org.hibernate.type.descriptor.sql.BasicExtractor: TRACE
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
  instance:
    prefer-ip-address: true

服务消费者order

server:
  port: 8010
spring:
  application:
    name: microservice-consumer-order
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
  instance:
    prefer-ip-address: true

启动类
@LoadBalanced

@EnableDiscoveryClient
@SpringBootApplication
public class ConsumerOrderApplication {
  @Bean
  @LoadBalanced
  public RestTemplate restTemplate() {
    return new RestTemplate();
  }

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

调用user

@RestController
public class OrderController {
  private static final Logger LOGGER = LoggerFactory.getLogger(OrderController.class);
  @Autowired
  private RestTemplate restTemplate;
  @Autowired
  private LoadBalancerClient loadBalancerClient;

  @GetMapping("/user/{id}")
  public User findById(@PathVariable Long id) {
    return this.restTemplate.getForObject("http://microservice-provider-user/" + id, User.class);
  }

  @GetMapping("/user/getIpAndPort")
  public String getIpAndPort() {
      return this.restTemplate.getForObject("http://microservice-provider-user/getIpAndPort", String.class);
  }

  @GetMapping("/user1/getIpAndPort")
  public String getUserIpAndPort() {
      return this.restTemplate.getForObject("http://microservice-provider-user222/getIpAndPort", String.class);
  }

  @GetMapping("/log-user-instance")
  public void logUserInstance() {
    ServiceInstance serviceInstance = this.loadBalancerClient.choose("microservice-provider-user");
    // 打印当前选择的是哪个节点
    OrderController.LOGGER.info("{}:{}:{}", serviceInstance.getServiceId(), serviceInstance.getHost(), serviceInstance.getPort());
  }
}

/**
 * 使用RibbonClient，为特定name的Ribbon Client自定义配置.
 * 使用@RibbonClient的configuration属性，指定Ribbon的配置类.
 */
@Configuration
@RibbonClient(name = "microservice-provider-user", 
configuration = RibbonConfiguration.class)
public class ProviderUserConfiguration {}

/**
 * 该类为Ribbon的配置类
 * 注意：该类不应该在主应用程序上下文的@ComponentScan 中。
 */
@Configuration
public class RibbonConfiguration {
  @Bean
  public IRule ribbonRule() {
    // 负载均衡规则，改为随机
    return new RandomRule();
  }
}

包结构图

配置负载均衡策略

server:
  port: 8010
spring:
  application:
    name: microservice-consumer-order
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
  instance:
    prefer-ip-address: true

microservice-provider-user:
  ribbon:
    NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RandomRule

ribbon脱离eureka实现负载均衡

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

server:
  port: 8010
spring:
  application:
    name: microservice-consumer-order
microservice-provider-user:
  ribbon:
    listOfServers: localhost:8001,localhost:8002
    NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RandomRule