How to use Spring Boot feign client for Oauth2 authentication?

Question

I have an oauth server at localhost and want to call it from another service uisng feign-client for authenticating me and giving me some token.

Here is how i pass my username,password and grant type i postman

Here is how my pass the basic auth details

How to do the same functionality using FeignClient in Spring Boot?

Answer 1

put @EnableFeignClients in the spring boot main application java class . create after an Feign client interface to call the web service :

    @FeignClient(value = "service-auth",
        configuration = ClientConfig.class,
        fallbackFactory = ClientFallbackFactory.class,
        url = "http://localhost:10000/oauth/")
    public interface GenericAbstractClient {


    @RequestMapping(value="/token",
            method = RequestMethod.POST,
            consumes = MediaType.APPLICATION_JSON_UTF8_VALUE,
            produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
    ResponseVo auth(@RequestBody RequestVo body);


}

and ClientFallbackFactory as :

    @Component
    class ClientFallbackFactory implements FallbackFactory<GenericAbstractClient> {

    private static final Logger LOGGER = LoggerFactory.getLogger(ClientFallbackFactory.class);


   

     @Override
      public GenericAbstractClient create(Throwable cause) {

    return new GenericAbstractClient () {


      @Override
      public ResponseVo oauth(RequestVo body) {
        LOGGER.warn("Hystrix exception", cause.getMessage());
        return null;
      }

    
    };
}
}

Your RequestBody might be a java class :

@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class RequestVo {


private String grant_type;
private String username;
private String password;

}

and The ResponseVo class :

    @Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class ResponseVo {


private String access_token;
private String token_type;
private String exprires_in;
private String scope;

}

and you can add thise config :

@Configuration
public class ClientConfig {


    private int connectTimeOutMillis = 120000;
    private int readTimeOutMillis = 120000;


    @Bean
    public Request.Options options() {
        return new Request.Options(connectTimeOutMillis, readTimeOutMillis);
    }
}