Spring Cloud 系列之负载均衡 Ribbon的示例代码

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

/**
 * Created with IntelliJ IDEA.
 *
 * @author Demo_Null
 * @date 2020/10/29
 * @description 消费者启动类
 */
@SpringBootApplication
@EnableDiscoveryClient
public class ConsumerApplication {
 public static void main(String[] args) {
  SpringApplication.run(ConsumerApplication.class, args);
 }
 
 @Bean
 @LoadBalanced
 public RestTemplate getRestTemplate() {
  return new RestTemplate();
 }
}

/**
 * Created with IntelliJ IDEA.
 *
 * @author Demo_Null
 * @date 2020/10/29
 * @description
 */
@RestController
@RequestMapping("/consumer")
public class ConsumerController {

 @Autowired
 private DiscoveryClient discoveryClient;

 @Autowired
 private RestTemplate restTemplate;

 @GetMapping("/go")
 public void go() {
  List<ServiceInstance> providerServer = discoveryClient.getInstances("ProviderServer");

  if (0 == providerServer.size()) {
   return;
  }

  ServiceInstance serviceInstance = providerServer.get(0);
  String url = serviceInstance.getUri() + "/provider/get";
  System.out.println(url + " --- ");
  String str = restTemplate.getForObject(url, String.class);
  System.out.println(str);

 }
}

@RestController
@RequestMapping("/consumer")
public class ConsumerController {

 @Autowired
 private RestTemplate restTemplate;


 @GetMapping("/go")
 public void go() {
  String url = "http://ProviderServer/provider/get";

  String str = restTemplate.getForObject(url, String.class);
  System.out.println(str);
 }
}

@Configuration
public class MyRibbonRule {

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

@SpringBootApplication
@EnableDiscoveryClient
// 用 name 来指定调用的服务名称，configuration 指定自定义配置类
@RibbonClient(name = "ProviderServer", configuration = MyRibbonRule.class)
public class ConsumerApplication {

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

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

# 这种配置的优先级低于配置类
# 想要调用的服务名称，即服务提供者名称
ProviderServer:
 ribbon:
 NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RandomRule