How can I change the feign URL during the runtime?

问题

@FeignClient(name = "test", url="http://xxxx")

How can I change the feign URL (url="http://xxxx") during the runtime? because the URL can only be determined at run time.

回答1:

Feign has a way to provide the dynamic URLs and endpoints at runtime.

The following steps have to be followed:

In the FeignClient interface we have to remove the URL parameter. We have to use @RequestLine annotation to mention the REST method (GET, PUT, POST, etc.):

@FeignClient(name="customerProfileAdapter")
public interface CustomerProfileAdaptor {

    // @RequestMapping(method=RequestMethod.GET, value="/get_all")
    @RequestLine("GET")
    public List<Customer> getAllCustomers(URI baseUri); 

    // @RequestMapping(method=RequestMethod.POST, value="/add")
    @RequestLine("POST")
    public ResponseEntity<CustomerProfileResponse> addCustomer(URI baseUri, Customer customer);

    @RequestLine("DELETE")
    public ResponseEntity<CustomerProfileResponse> deleteCustomer(URI baseUri, String mobile);
}

In RestController you have to import FeignClientConfiguration
You have to write one RestController constructor with encoder and decoder as parameters.
You need to build the FeignClient with the encoder, decoder.
While calling the FeignClient methods, provide the URI (BaserUrl + endpoint) along with rest call parameters if any.

@RestController
@Import(FeignClientsConfiguration.class)
public class FeignDemoController {

    CustomerProfileAdaptor customerProfileAdaptor;

    @Autowired
    public FeignDemoController(Decoder decoder, Encoder encoder) {
        customerProfileAdaptor = Feign.builder().encoder(encoder).decoder(decoder) 
           .target(Target.EmptyTarget.create(CustomerProfileAdaptor.class));
    }

    @RequestMapping(value = "/get_all", method = RequestMethod.GET)
    public List<Customer> getAllCustomers() throws URISyntaxException {
        return customerProfileAdaptor
            .getAllCustomers(new URI("http://localhost:8090/customer-profile/get_all"));
    }

    @RequestMapping(value = "/add", method = RequestMethod.POST)
    public ResponseEntity<CustomerProfileResponse> addCustomer(@RequestBody Customer customer) 
            throws URISyntaxException {
        return customerProfileAdaptor
            .addCustomer(new URI("http://localhost:8090/customer-profile/add"), customer);
    }

    @RequestMapping(value = "/delete", method = RequestMethod.POST)
    public ResponseEntity<CustomerProfileResponse> deleteCustomer(@RequestBody String mobile)
            throws URISyntaxException {
        return customerProfileAdaptor
            .deleteCustomer(new URI("http://localhost:8090/customer-profile/delete"), mobile);
    }
}

回答2:

You can add an unannotated URI parameter (that can potentially be determined at runtime) and that will be the base path that will be used for the request. E.g.:

@FeignClient(name = "dummy-name", url = "https://this-is-a-placeholder.com")
public interface MyClient {
    @PostMapping(path = "/create")
    UserDto createUser(URI baseUrl, @RequestBody UserDto userDto);
}

And then the usage will be:

@Autowired 
private MyClient myClient;
...
URI determinedBasePathUri = URI.create("https://my-determined-host.com");
myClient.createUser(determinedBasePathUri, userDto);

This will send a POST request to https://my-determined-host.com/create (source).

回答3:

You can create the client manually:

@Import(FeignClientsConfiguration.class)
class FooController {

    private FooClient fooClient;

    private FooClient adminClient;

    @Autowired
    public FooController(ResponseEntityDecoder decoder, SpringEncoder encoder, Client client) {
        this.fooClient = Feign.builder().client(client)
            .encoder(encoder)
            .decoder(decoder)
            .requestInterceptor(new BasicAuthRequestInterceptor("user", "user"))
            .target(FooClient.class, "http://PROD-SVC");
        this.adminClient = Feign.builder().client(client)
            .encoder(encoder)
            .decoder(decoder)
            .requestInterceptor(new BasicAuthRequestInterceptor("admin", "admin"))
            .target(FooClient.class, "http://PROD-SVC");
     }
}

Please see the documentation: https://cloud.spring.io/spring-cloud-netflix/multi/multi_spring-cloud-feign.html#_creating_feign_clients_manually

回答4:

I don`t know if you use spring depend on multiple profile. for example: like(dev,beta,prod and so on)

if your depend on different yml or properties. you can define FeignClientlike:(@FeignClient(url = "${feign.client.url.TestUrl}", configuration = FeignConf.class))

then

define

feign:
  client:
    url:
      TestUrl: http://dev:dev

in your application-dev.yml

define

feign:
  client:
    url:
      TestUrl: http://beta:beta

in your application-beta.yml (I prefer yml).

......

thanks god.enjoy.

回答5:

In interface you can change url by Spring annotations. The base URI is configured in yml Spring configuration.

   @FeignClient(
            name = "some.client",
            url = "${some.serviceUrl:}",
            configuration = FeignClientConfiguration.class
    )

public interface SomeClient {

    @GetMapping("/metadata/search")
    String search(@RequestBody SearchCriteria criteria);

    @GetMapping("/files/{id}")
    StreamingResponseBody downloadFileById(@PathVariable("id") UUID id);

}

来源：https://stackoverflow.com/questions/43733569/how-can-i-change-the-feign-url-during-the-runtime

标签

spring-cloud

spring-cloud-feign