Details of springcloud Feign Hystrix support

This article introduces springcloud Feign's Hystrix support and shares it with you as follows:

1. fallback added to Feign client

@FeignClient(name="springboot-h2", fallback=HystrixClientFallback.class) // in fallback Property that specifies a circuit breaker fallback 
public interface UserFeignClient { 
// @GetMapping("/user/{id}") 
  @RequestMapping(value = "/user/{id}", method = RequestMethod.GET) 
  User findById(@PathVariable("id") Long id); 
   
  @RequestMapping(value="/users", method=RequestMethod.GET) 
  List<User> findAll(); 
   
  @RequestMapping(value="/post/user", method=RequestMethod.POST) 
  User save(@RequestBody User user); 
} 

2. Write HystrixClientFallback classes

@Component // join spring bean In the  
public class HystrixClientFallback implements UserFeignClient{ 
 
  @Override 
  public User findById(Long id) { 
    User u = new User(); 
    u.setName(" Temporary name "); 
    u.setUsername(" anonymous "); 
    return u; 
  } 
 
  @Override 
  public List<User> findAll() { 
    return null; 
  } 
 
  @Override 
  public User save(User user) { 
    return null; 
  } 
} 

3. Join Hystrix support

@EnableCircuitBreaker 

4. Test

Instead of starting the underlying dependent service, start the service directly, and then test it. The result found in the browser is:

{" id ": null," username ":" anonymous ", and "name" : "temporary name", "age" : null, "balance" : null}

Instead of reporting an exception as expected, it goes into the findById method in the HystrixClientFallback class.