Feign自定义重试策略及超时时间详解

@Slf4j
@Configuration
public class FeignAutoConfiguration {
    public static final int CONNECT_TIME_OUT_MILLIS = 5000;
    public static final int READ_TIME_OUT_MILLIS = 12000;


    @Autowired(required = false)
    private List<AnnotatedParameterProcessor> parameterProcessors = new ArrayList<>();

    @Bean
    public Encoder encoder(ObjectFactory<HttpMessageConverters> messageConverters) {
        Encoder encoder = new SpringEncoder(messageConverters);
        return encoder;
    }

    @Bean
    public Decoder decoder(ObjectFactory<HttpMessageConverters> messageConverters) {
        Decoder decoder = new SpringDecoder(messageConverters);
        return decoder;
    }

    @Bean
    public Contract feignContract(@Qualifier("mvcConversionService") ConversionService feignConversionService) {
        return new SpringMvcContract(this.parameterProcessors, feignConversionService);
    }

    //全局超时配置
    @Bean
    public Request.Options options() {
        return new Request.Options(CONNECT_TIME_OUT_MILLIS, READ_TIME_OUT_MILLIS);
    }

    //全局重试策略
    @Bean
    public Retryer feignRetryer() {
        return Retryer.NEVER_RETRY;
    }

}

// 引入全局配置
@Import(value = {FeignAutoConfiguration.class})
@Configuration
public class CustomFeignClientConfiguration {
    @Qualifier("feignClient")
    @Autowired
    private Client client;
    @Autowired
    private Encoder encoder;
    @Autowired
    private Decoder decoder;
    @Autowired
    private Contract contract;
    @Autowired
    private Request.Options options;
    @Autowired
    private Retryer retryer;
    /**
     * 自定义RoleClient; 【后续扩展自定义Feign的模仿本方法配置即可】
     *
     * @return
     */
    @Bean
    public RoleClient customRoleClient() {
        //自定义超时时间，connectTimeout 5s  ; readTimeout  10s;
        Request.Options options = new Request.Options(5, TimeUnit.SECONDS, 10, TimeUnit.SECONDS, true);
        //重试2次
        Retryer.Default retryer = new Retryer.Default(100, SECONDS.toMillis(1), 2);
        return getCustomFeignClient(RoleClient.class, options, retryer);
    }
    /**
     * 手动构建feignClient工具方法
     *
     * @param clazz
     * @param options
     * @param retryer
     * @param <T>
     * @return
     */
    private <T> T getCustomFeignClient(Class<T> clazz, Request.Options options, Retryer retryer) {
        //只需要对其中的超时和重试配置自定义，其他的还需要使用全局配置
        //通过反射获取@FeignClient注解
        FeignClient annotation = clazz.getAnnotation(FeignClient.class);
        return Feign.builder()
                .client(client)
                .options(options == null ? this.options : options)
                .retryer(retryer == null ? this.retryer : retryer)
                .contract(contract)
                .encoder(encoder)
                .decoder(decoder)
                .target(clazz, "http://" + annotation.value());
    }
}

// 注入
@Resource
private RoleClient roleClient;
@Resource
private RoleClient customRoleClient;
public void checkRoleDataAuth(String roleId){
    // 使用时直接替换feignClient即可
    //    ResultBody resultBody = roleClient.checkRoleDataAuth(roleId);
    ResultBody resultBody = customRoleClient.checkRoleDataAuth(roleId);
    if (!resultBody.isSuccess()){
        throw new BaseException(resultBody.getCode(),resultBody.getMessage());
    }
}

//feign方法调用实现
@Override
public Object invoke(Object[] argv) throws Throwable {
  RequestTemplate template = buildTemplateFromArgs.create(argv);
  //获取当前方法的Request.Options超时配置
  Options options = findOptions(argv);
  Retryer retryer = this.retryer.clone();
  while (true) {
    try {
      //方法调用
      return executeAndDecode(template, options);
    } catch (RetryableException e) {
      //重试
      try {
        retryer.continueOrPropagate(e);
      } catch (RetryableException th) {
        Throwable cause = th.getCause();
        if (propagationPolicy == UNWRAP && cause != null) {
          throw cause;
        } else {
          throw th;
        }
      }
      if (logLevel != Logger.Level.NONE) {
        logger.logRetry(metadata.configKey(), logLevel);
      }
      continue;
    }
  }
}
//从feignClient方法参数列表中找到Request.Options实例对象
  Options findOptions(Object[] argv) {
    // 如果方法没有参数，使用client配置
    if (argv == null || argv.length == 0) {
      return this.options;
    }
    //查找并使用参数列表的Request.Options，若不存在则使用client配置
    return Stream.of(argv)
        .filter(Options.class::isInstance)
        .map(Options.class::cast)
        .findFirst()
        .orElse(this.options);
  }

@FeignClient(value = UserConstants.SERVER_NAME)
public interface RoleClient {
    @GetMapping(value = "/openfeign/role/checkRoleDataAuth")
    ResultBody checkRoleDataAuth(@RequestParam("roleId") String roleId, Request.Options options);
}

//自定义超时时间，connectTimeout 5s  ; readTimeout  60s;
Request.Options options = new Request.Options(5, TimeUnit.SECONDS, 60, TimeUnit.SECONDS, true);
ResultBody resultBody = roleClient.checkRoleDataAuth(roleId, options);
//传入null，使用client中的超时配置
ResultBody resultBody = roleClient.checkRoleDataAuth(roleId, null);