2021-11-11 springboot feign 如何配置

springboot feign 使用很方便, 只需要编写接口即可使用, 但是有时候需要登录绑定token, 每次手动传入token header 太不方便
可以通过target 配置,传入token

在配置文件中

  @Inject
  HttpService httpService; //用来获取token
  @Inject
  private Properties properties; //登录的账号密码等配置

  @Bean
  public Feign.Builder builder() {
    log.debug("default builder for external feign client");
    return new FeignBuilder(httpService, properties);
  }

写一个FeignBuilder

public class FeignBuilder extends Feign.Builder {
  private HttpService httpService;
  private Properties properties;

  public MfgFeignBuilder(HttpService httpService, Properties  properties) {
    this.httpService= httpService;
    this.properties= properties;
  }

  @Override
  public <T> T target(Target<T> target) {
    MfgTarget<T> mfgTarget = new MfgTarget<>(target, httpService, properties);
    return super.target(mfgTarget);
  }
}

重点, 写一个target

public class MfgTarget<T> implements Target<T> {
  private static final String AUTHENTICATE_REQUEST_URL = "/mfg-uaa/oauth/token?grant_type=client_credentials";
  private Target<T> wrappedTarget;
  private TenantService tenantService;
  private MfgProperties mfgProperties;


  public MfgTarget(Target<T> wrappedTarget, TenantService tenantService, MfgProperties mfgProperties) {
    this.wrappedTarget = wrappedTarget;
    this.tenantService = tenantService;
    this.mfgProperties = mfgProperties;
  }

  @Override
  public Class<T> type() {
    return wrappedTarget.type();
  }

  @Override
  public String name() {
    return wrappedTarget.name();
  }

  @Override
  public String url() {
    return wrappedTarget.url();
  }

  @Override
  public Request apply(RequestTemplate input) {
    if (input.url().indexOf("http") != 0) {
      input.target(url());
      final Map<String, Collection<String>> headers = input.headers();
      if (input.url().contains(AUTHENTICATE_REQUEST_URL)) {
        return input.request();
      }
      final String accessToken = tenantService.getAccessToken(tenantInfo.getId(), tenantInfo.getPassword(), tenant);
      input.header(Contants.AUTHORIZATION, accessToken);
    }
    return input.request();
  }
}

这样, 每次请求的时候, 都会去tenantService中获取token, 如果没有则进行登录, 当然缓存token的逻辑存储在tenantService中了