Hystrix 断路器

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


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spring:
  application:
    name: hystrix
    
server:
  port: 3001
  
eureka:
  client:    
    service-url:
      defaultZone: http://eureka1:2001/eureka, http://eureka2:2002/eureka
      
ribbon:
  MaxAutoRetries: 1
  MaxAutoRetriesNextServer: 2
  OkToRetryOnAllOperations: true


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package cn.tedu.sp06;


import org.springframework.boot.SpringApplication;
import org.springframework.cloud.client.SpringCloudApplication;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;


//@EnableCircuitBreaker
//@EnableDiscoveryClient
//@SpringBootApplication


@SpringCloudApplication
public class Sp06RibbonApplication {


  @LoadBalanced
  @Bean
  public RestTemplate getRestTemplate() {
    SimpleClientHttpRequestFactory f = new SimpleClientHttpRequestFactory();
    f.setConnectTimeout(1000);
    f.setReadTimeout(1000);
    return new RestTemplate(f);
    
    //RestTemplate 中默认的 Factory 实例中，两个超时属性默认是 -1，
    //未启用超时，也不会触发重试
    //return new RestTemplate();
  }


  public static void main(String[] args) {
    SpringApplication.run(Sp06RibbonApplication.class, args);
  }


}


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package cn.tedu.sp06.controller;


import java.util.List;


import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;


import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
import cn.tedu.sp01.pojo.Item;
import cn.tedu.sp01.pojo.Order;
import cn.tedu.sp01.pojo.User;
import cn.tedu.web.util.JsonResult;


@RestController
public class RibbonController {
  @Autowired
  private RestTemplate rt;
  
  @GetMapping("/item-service/{orderId}")
  @HystrixCommand(fallbackMethod = "getItemsFB") //指定降级方法的方法名
  public JsonResult<List<Item>> getItems(@PathVariable String orderId) {
    return rt.getForObject("http://item-service/{1}", JsonResult.class, orderId);
  }


  @PostMapping("/item-service/decreaseNumber")
  @HystrixCommand(fallbackMethod = "decreaseNumberFB")
  public JsonResult decreaseNumber(@RequestBody List<Item> items) {
    return rt.postForObject("http://item-service/decreaseNumber", items, JsonResult.class);
  }


  /////////////////////////////////////////
  
  @GetMapping("/user-service/{userId}")
  @HystrixCommand(fallbackMethod = "getUserFB")
  public JsonResult<User> getUser(@PathVariable Integer userId) {
    return rt.getForObject("http://user-service/{1}", JsonResult.class, userId);
  }


  @GetMapping("/user-service/{userId}/score") 
  @HystrixCommand(fallbackMethod = "addScoreFB")
  public JsonResult addScore(@PathVariable Integer userId, Integer score) {
    return rt.getForObject("http://user-service/{1}/score?score={2}", JsonResult.class, userId, score);
  }
  
  /////////////////////////////////////////
  
  @GetMapping("/order-service/{orderId}")
  @HystrixCommand(fallbackMethod = "getOrderFB")
  public JsonResult<Order> getOrder(@PathVariable String orderId) {
    return rt.getForObject("http://order-service/{1}", JsonResult.class, orderId);
  }


  @GetMapping("/order-service")
  @HystrixCommand(fallbackMethod = "addOrderFB")
  public JsonResult addOrder() {
    return rt.getForObject("http://order-service/", JsonResult.class);
  }
  
  /////////////////////////////////////////


    //降级方法的参数和返回值，需要和原始方法一致，方法名任意
  public JsonResult<List<Item>> getItemsFB(String orderId) {
    return JsonResult.err("获取订单商品列表失败");
  }
  public JsonResult decreaseNumberFB(List<Item> items) {
    return JsonResult.err("更新商品库存失败");
  }
  public JsonResult<User> getUserFB(Integer userId) {
    return JsonResult.err("获取用户信息失败");
  }
  public JsonResult addScoreFB(Integer userId, Integer score) {
    return JsonResult.err("增加用户积分失败");
  }
  public JsonResult<Order> getOrderFB(String orderId) {
    return JsonResult.err("获取订单失败");
  }
  public JsonResult addOrderFB() {
    return JsonResult.err("添加订单失败");
  }
}




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spring:
  application:
    name: hystrix
    
server:
  port: 3001
  
eureka:
  client:
    service-url:
      defaultZone: http://eureka1:2001/eureka, http://eureka2:2002/eureka
      
ribbon:
  MaxAutoRetriesNextServer: 2
  MaxAutoRetries: 1
  OkToRetryOnAllOperations: true
  
hystrix:
  command:
    default:
      execution:
        isolation:
          thread:
            timeoutInMilliseconds: 500
            


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