What causes "上传失败，服务器响应空 url:%s param:%s" in binarywang/WxJava?

Retry the upload — null/empty bodies are frequently transient.

binarywang/WxJava · error · WxErrorException

上传失败，服务器响应空 url:%s param:%s

Error message

上传失败，服务器响应空 url:%s param:%s

What it means

The OkHttp upload executor throws when response.body() is null or responseBody.string() is empty after the multipart POST. Same fast-fail semantics as the other three upload executors: an empty body cannot be parsed into a WxError. OkHttp distinguishes a null body from an empty string body and treats both as failure here.

Source

Thrown at weixin-java-common/src/main/java/me/chanjar/weixin/common/executor/CommonUploadRequestExecutorOkHttpImpl.java:52

    MultipartBody.Builder bodyBuilder = new MultipartBody.Builder()
      .setType(MediaType.get("multipart/form-data"))
      .addFormDataPart(param.getName(), param.getData().getFileName(), requestBody);

    // 添加额外的表单字段
    if (param.getFormFields() != null && !param.getFormFields().isEmpty()) {
      for (java.util.Map.Entry<String, String> entry : param.getFormFields().entrySet()) {
        bodyBuilder.addFormDataPart(entry.getKey(), entry.getValue());
      }
    }

    RequestBody body = bodyBuilder.build();
    Request request = new Request.Builder().url(uri).post(body).build();

    try (Response response = requestHttp.getRequestHttpClient().newCall(request).execute()) {
      ResponseBody responseBody = response.body();
      String responseContent = responseBody == null ? "" : responseBody.string();
      if (responseContent.isEmpty()) {
        throw new WxErrorException(String.format("上传失败，服务器响应空 url:%s param:%s", uri, param));
      }
      WxError error = WxError.fromJson(responseContent, wxType);
      if (error.getErrorCode() != 0) {
        throw new WxErrorException(error);
      }
      return responseContent;
    }
  }

  /**
   * 通用上传输入 到 OkHttp 请求提 适配器
   */
  @AllArgsConstructor
  public static class CommonUpdateDataToRequestBodyAdapter extends RequestBody {

    private static final MediaType CONTENT_TYPE = MediaType.get("application/octet-stream");

    private CommonUploadData data;

View on GitHub (pinned to 1c43293a3c)

Solutions

Retry the upload — null/empty bodies are frequently transient.
Check apiHostUrl/proxy and body-size limits.
Verify the endpoint path and that WeChat expects this upload verb/content-type.
Log response.code() and headers to localise the empty-body source.

Example fix

// before
String r = service.upload(param);

// after
try {
  return service.upload(param);
} catch (WxErrorException e) {
  if (e.getMessage() != null && e.getMessage().contains("服务器响应空")) {
    return service.upload(param);
  }
  throw e;
}

Defensive patterns

Strategy: retry

Try / catch

int attempts = 0;
while (true) {
  try {
    return service.upload(param);
  } catch (WxErrorException e) {
    boolean empty = e.getMessage() != null && e.getMessage().contains("服务器响应空");
    if (!empty || ++attempts > 2) throw e;
    Thread.sleep(1000L * attempts);
  }
}

Prevention

Verify the OkHttp client's proxy/apiHostUrl configuration.
Confirm upload size is within endpoint limits.
Log response.code() and headers when this fires to localise the empty/null body.

When it happens

Trigger: OkHttp receives a 204 or a 200 with a null/empty body during upload; gateway/WAF strips the response; the connection is closed before any body bytes.

Common situations: OkHttp backend behind a stripping proxy; large upload silently rejected by an intermediary; transient reset; wrong endpoint returning empty.

Related errors

AI-assisted analysis of binarywang/WxJava@1c43293a3c (2026-08-14). Data as JSON: /api/errors/c7cb7390bd0eb821. Report an issue: GitHub.