apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/service/ConfigsExportService.java/ConfigsExportService/writeAppInfoToZip
class ConfigsExportService:  private void writeAppInfoToZip(List<App> apps, ZipOutputStream zipOutputStream) {
    logger.info("to import app size = {}", apps.size());

    final Consumer<App> appConsumer =
        app -> {
          try {
            synchronized (zipOutputStream) {
              String fileName = ConfigFileUtils.genAppInfoPath(app);
              String content = gson.toJson(app);

              writeToZip(fileName, content, zipOutputStream);
            }
          } catch (IOException e) {
            logger.error("Write error. {}", app);
            throw new ServiceException("Write app error. {}", e);
          }
        };

    apps.forEach(appConsumer);
  }