SpringCloud微服务之Hystrix组件实现服务熔断的方法

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

/**
 * 服务熔断调用方法
 */
public String getDefaultInfo (){
  return "服务被熔断" ;
}

/**
 * 简单配置
 */
@RequestMapping("/showInfo1")
@HystrixCommand(fallbackMethod = "getDefaultInfo")
public String showInfo1 (){
  return restTemplate.getForObject(server_name+"/getInfo",String.class) ;
}

/**
 * 复杂配置
 */
@RequestMapping("/showInfo2")
@HystrixCommand(
    fallbackMethod = "getDefaultInfo",
    commandProperties={
        // 降级处理超时时间设置
        @HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds", value = "3000"),
        // 任意时间点允许的最高并发数。超过该设置值后，拒绝执行请求。
        @HystrixProperty(name = "fallback.isolation.semaphore.maxConcurrentRequests", value = "1000"),
    },
    // 配置执行的线城池
    threadPoolProperties = {
        @HystrixProperty(name = "coreSize", value = "20"),
        @HystrixProperty(name = "maxQueueSize", value = "-1"),
    },
    // 该异常不执行熔断，去执行该异常抛出的自己逻辑
    ignoreExceptions = {ServiceException.class}
)
public String showInfo2 (){
  String value = "" ;
  // 测试配置异常不熔断
  // 响应：{"code":500,"msg":"运行异常"}
  if (value.equals("")){
    throw new ServiceException("运行异常") ;
  }
  // 该异常被熔断
  // if (value.equals("")){
  //   throw new RuntimeException("抛出错误") ;
  // }
  return restTemplate.getForObject(server_name+"/getInfo",String.class) ;
}

@FeignClient(value = "NODE02-PROVIDER",fallback = FallbackService.class)
public interface GetAuthorService {
  @RequestMapping(value = "/getAuthorInfo/{authorId}",method = RequestMethod.GET)
  String getAuthorInfo (@PathVariable("authorId") String authorId) ;
}

@Component
public class FallbackService implements GetAuthorService {
  @Override
  public String getAuthorInfo(String authorId) {
    return "服务被熔断"+authorId;
  }
}

feign:
 hystrix:
  enabled: true

@SpringBootApplication(scanBasePackages = {"cloud.node02.consume","cloud.block.code.service"})
@EnableEurekaClient  // 本服务启动后会自动注册进eureka服务中
@EnableDiscoveryClient
// 因为包名路径不同，需要加basePackages属性
@EnableFeignClients(basePackages={"cloud.block.code.service"})
public class Application_8002 {
  public static void main(String[] args) {
    SpringApplication.run(Application_8002.class,args) ;
  }
}