Spring Cloud Alibaba 使用 Feign+Sentinel 完成熔断的示例

compile("org.springframework.cloud:spring-cloud-starter-openfeign")

package com.skypyb.sc.feign;

import com.skypyb.sc.entity.User;

import org.springframework.cloud.openfeign.FeignClient;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestMethod;

@FeignClient ( "sc-demo-microservice-user" )

public interface UserFeignClient {

  @RequestMapping (value = "/user/{id}" ,method = RequestMethod.GET)

  public User getUser( @PathVariable ( "id" ) Long id);

}

package com.skypyb.sc.controller;

import com.skypyb.sc.entity.User;

import com.skypyb.sc.feign.UserFeignClient;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.cloud.client.ServiceInstance;

import org.springframework.cloud.client.discovery.DiscoveryClient;

import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

import org.springframework.web.client.RestTemplate;

import java.util.List;

@RestController

@RequestMapping ( "/movie" )

public class MovieController {

  private Logger logger = LoggerFactory.getLogger(MovieController. class );

  @Autowired

  private UserFeignClient userFeignClient;

  @GetMapping ( "/user/{id}" )

  public User getUser( @PathVariable ( "id" ) Long id) {

   return userFeignClient.getUser(id);

  }

}

package com.skypyb.sc.config;

import feign.Logger;

import feign.auth.BasicAuthRequestInterceptor;

import org.springframework.context.annotation.Bean;

public class FeignConfiguration {

  @Bean

  public Logger.Level feignLog() {

   return Logger.Level.FULL;

  }

  /**

   * 使用指定的用户名和密码验证所有请求

   * @return

   */

  @Bean

  public BasicAuthRequestInterceptor basicAuthRequestInterceptor(){

   return new BasicAuthRequestInterceptor( "user" , "614" );

  }

}

@FeignClient(name = "sc-demo-microservice-user" , configuration = FeignConfiguration.class)

< dependency >

  < groupId >com.alibaba.cloud</ groupId >

  < artifactId >spring-cloud-starter-alibaba-sentinel</ artifactId >

</ dependency >

< dependency >

  < groupId >org.springframework.cloud</ groupId >

  < artifactId >spring-cloud-starter-openfeign</ artifactId >

</ dependency >

package com.skypyb.provider.feign;

import com.skypyb.provider.fallback.HelloServiceFallback;

import org.springframework.cloud.openfeign.FeignClient;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RequestMapping;

/**

  * Feign客户端

  * 指定调用 sc-demo-alibaba-provider 的服务

  */

@FeignClient (value = "sc-demo-alibaba-provider" ,fallback = HelloServiceFallback. class )

public interface NacosHelloFeign {

  @RequestMapping (value = "/provider/hello/{msg}" )

  String hello( @PathVariable ( "msg" ) String msg);

}

package com.skypyb.provider.controller;

import com.skypyb.provider.feign.NacosHelloFeign;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.cloud.client.ServiceInstance;

import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

import org.springframework.web.client.RestTemplate;

import javax.annotation.Resource;

@RequestMapping ( "/consumer" )

@RestController

public class NacosConsumerController {

  @Autowired

  private LoadBalancerClient loadBalancerClient;

  @Autowired

  private RestTemplate restTemplate;

  @Resource

  private NacosHelloFeign nacosHelloFeign;

  @GetMapping (value = "/hello/{msg}" )

  public String hello( @PathVariable ( "msg" ) String msg) {

   //使用 LoadBalanceClient 和 RestTemplate 结合的方式来访问

   ServiceInstance serviceInstance = loadBalancerClient.choose( "sc-demo-alibaba-provider" );

   String url = String.format( "http://%s:%s/provider/hello/%s" ,

     serviceInstance.getHost(), serviceInstance.getPort(), msg);

   return restTemplate.getForObject(url, String. class );

  }

  @GetMapping (value = "/hello/feign/{msg}" )

  public String helloFeign( @PathVariable ( "msg" ) String msg) {

   return nacosHelloFeign.hello(msg);

  }

}

package com.skypyb.provider.fallback;

import com.skypyb.provider.feign.NacosHelloFeign;

import org.springframework.stereotype.Component;

/**

  * 熔断类

  * 要是 Feign 的接口调用失败(或者被快速失败)就会走这个类的方法进行处理

  */

@Component

public class HelloServiceFallback implements NacosHelloFeign {

  @Override

  public String hello(String msg) {

   return "触发熔断机制~" ;

  }

}

package com.skypyb.provider.fallback;

import com.skypyb.provider.feign.NacosHelloFeign;

import org.springframework.stereotype.Component;

/**

  * 熔断类

  * 要是 Feign 的接口调用失败(或者被快速失败)就会走这个类的方法进行处理

  */

@Component

public class HelloServiceFallback implements NacosHelloFeign {

  @Override

  public String hello(String msg) {

   return "触发熔断机制~" ;

  }

}

feign:

  sentinel:

  enabled: true

docker pull bladex /sentinel-dashboard

docker run --name sentinel -d -p 8858:8858 -d bladex /sentinel-dashboard

spring:

  application:

  name: sc-demo-alibaba-consumer

  cloud:

  nacos:

   discovery:

   server-addr: 192.168.1.14:8848 #注册进 nacos

  sentinel:

    transport:

    port: 18081 #这个端口的意思是自己这个服务开个端口和 sentinel 控制台交互

    dashboard: 192.168.1.14:8858 # sentinel 控制台的端口

server:

  port: 8081

feign:

  sentinel:

  enabled: true

management:

  endpoints:

  web:

   exposure:

   include: "*"