When testing the Hystrix fallback behavior of my Feign API, I get an error, when I expect it to succeed.
Feign interface:
This is the api to the external service.
@FeignClient(name = "book", fallback = BookAPI.BookAPIFallback.class)
public interface BookAPI {
@RequestMapping("/")
Map<String, String> getBook();
@Component
class BookAPIFallback implements BookAPI {
@Override
@RequestMapping("/")
public Map<String, String> getBook() {
Map<String, String> fallbackmap = new HashMap<>();
fallbackmap.put("book", "fallback book");
return fallbackmap;
}
}
}
Test class
This test exists just to verify fallback behavior:
@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = NONE)
public class BookServiceClientTest {
@MockBean
RestTemplate restTemplate;// <---- @LoadBalanced bean
@Autowired
private BookServiceClient bookServiceClient;
@Before
public void setup() {
when(restTemplate.getForObject(anyString(), any()))
.thenThrow(new RuntimeException("created a mock failure"));
}
@Test
public void fallbackTest() {
assertThat(bookServiceClient.getBook())
.isEqualTo(new BookAPI.BookAPIFallback().getBook().get("book")); // <--- I thought this should work
}
}
config files
application.yml
These files show configuration that might be relevant:
feign:
hystrix:
enabled: true
test/application.yml
eureka:
client:
enabled: false
The Question
Everything works fine when running the apps.
But when running this test, I get the below error.
Naturally, it's a test, so I'm trying to bypass the lookup anyway.
java.lang.RuntimeException: com.netflix.client.ClientException: Load balancer does not have available server for client: book
at org.springframework.cloud.netflix.feign.ribbon.LoadBalancerFeignClient.execute(LoadBalancerFeignClient.java:71)
at feign.SynchronousMethodHandler.executeAndDecode(SynchronousMethodHandler.java:97)
What am I missing?
Addendums
Application class
@SpringBootApplication
@EnableCircuitBreaker
@EnableDiscoveryClient
@EnableFeignClients
public class LibraryApplication {
public static void main(String[] args) {
SpringApplication.run(LibraryApplication.class, args);
}
}
LibraryController
@Controller
public class LibraryController {
private final BookServiceClient bookService;
public LibraryController(BookServiceClient bookServiceClient) {
this.bookService = bookServiceClient;
}
@GetMapping("/")
String getLibrary(Model model) {
model.addAttribute("msg", "Welcome to the Library");
model.addAttribute("book", bookService.getBook());
return "library";
}
}
There are no other classes.
