code: @Override
      public void write(List<? extends ManifestEntry> items) throws Exception {
          for (ManifestEntry entry : items) {
              try {
                  String contentId = entry.getContentId();
                  String checksum = entry.getChecksum();
  
                  File file = new File(this.contentDir, contentId);
                  if (!file.exists()) {
                      String message =
                          MessageFormat.format("content ({0}) not found in " +
                                               "path ({1}) for restore ({2})",
                                               contentId,
                                               file.getAbsolutePath(),
                                               restorationId);
                      log.error(message);
                      addError(message);
                  } else {
                      ChecksumUtil checksumUtil = new ChecksumUtil(Algorithm.MD5);
  
                      String fileChecksum = checksumUtil.generateChecksum(file);
                      if (!checksum.equals(fileChecksum)) {
                          String message =
                              MessageFormat.format("content id ({0}) manifest " +
                                                   "checksum ({1})  does not match " +
                                                   "file ({2}) checksum ({3})",
                                                   contentId,
                                                   checksum,
                                                   file.getAbsolutePath(),
                                                   fileChecksum);
                          log.error(message);
                          addError(message);
                      } else {
                          log.debug("successfully verified entry {}", entry);
                      }
                  }
  
              } catch (Exception ex) {
                  String message = "failed to verify " + entry + ": " + ex.getMessage();
                  log.error(message, ex);
                  addError(message);
              }
          }
      }
docs: /*
  (non-Javadoc)
  
  @see org.springframework.batch.item.ItemWriter#write(java.util.List)