protected void doGetFile(final HttpServletRequest request, final HttpServletResponse response,      final StorageFileItem file) throws IOException  {    // ETag, in "shaved" form of {SHA1{e5c244520e897865709c730433f8b0c44ef271f1}} (without quotes)    // or null if file does not have SHA1 (like Virtual) or generated items (as their SHA1 would correspond to template,    // not to actual generated content).    final String etag;    if (!file.isContentGenerated() && !file.isVirtual()        && file.getRepositoryItemAttributes().containsKey(StorageFileItem.DIGEST_SHA1_KEY)) {      etag = "{SHA1{" + file.getRepositoryItemAttributes().get(StorageFileItem.DIGEST_SHA1_KEY) + "}}";      // tag header ETag: "{SHA1{e5c244520e897865709c730433f8b0c44ef271f1}}", quotes are must by RFC      response.setHeader("ETag", "\"" + etag + "\"");    }    else {      etag = null;    }    // content-type    response.setHeader("Content-Type", file.getMimeType());    // last-modified    response.setDateHeader("Last-Modified", file.getModified());    // content-length, if known    if (file.getLength() != ContentLocator.UNKNOWN_LENGTH) {      // Note: response.setContentLength Servlet API method uses ints (max 2GB file)!      // TODO: apparently, some Servlet containers follow serlvet API and assume      // contents can have 2GB max, so even this workaround below in inherently unsafe.      // Jetty is checked, and supports this (uses long internally), but unsure for other containers      response.setHeader("Content-Length", String.valueOf(file.getLength()));    }    // handle conditional GETs only for "static" content, actual content stored, not generated    if (!file.isContentGenerated() && file.getResourceStoreRequest().getIfModifiedSince() != 0        && file.getModified() <= file.getResourceStoreRequest().getIfModifiedSince()) {      // this is a conditional GET using time-stamp      response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);    }    else if (!file.isContentGenerated() && file.getResourceStoreRequest().getIfNoneMatch() != null && etag != null        && file.getResourceStoreRequest().getIfNoneMatch().equals(etag)) {      // this is a conditional GET using ETag      response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);    }    else {      // NEXUS-5023 disable IE for sniffing into response content      response.setHeader("X-Content-Type-Options", "nosniff");      final List<Range<Long>> ranges = getRequestedRanges(request, file.getLength());      // pour the content, but only if needed (this method will be called even for HEAD reqs, but with content tossed      // away), so be conservative as getting input stream involves locking etc, is expensive      final boolean contentNeeded = "GET".equalsIgnoreCase(request.getMethod());      if (ranges.isEmpty()) {        if (contentNeeded) {          try (final InputStream in = file.getInputStream()) {            sendContent(in, response);          }        }      }      else if (ranges.size() > 1) {        response.setStatus(HttpServletResponse.SC_NOT_IMPLEMENTED);        renderer.renderErrorPage(request, response, file.getResourceStoreRequest(), new UnsupportedOperationException(            "Multiple ranges not yet supported!"));      }      else {        final Range<Long> range = ranges.get(0);        if (!isRequestedRangeSatisfiable(file, range)) {          response.setStatus(HttpServletResponse.SC_REQUESTED_RANGE_NOT_SATISFIABLE);          response.setHeader("Content-Length", "0");          response.setHeader("Content-Range", "bytes */" + file.getLength());          return;        }        final long bodySize = range.upperEndpoint() - range.lowerEndpoint();        response.setStatus(HttpServletResponse.SC_PARTIAL_CONTENT);        response.setHeader("Content-Length", String.valueOf(bodySize));        response.setHeader("Content-Range",            range.lowerEndpoint() + "-" + range.upperEndpoint() + "/" + file.getLength());        if (contentNeeded) {          try (final InputStream in = file.getInputStream()) {            in.skip(range.lowerEndpoint());            sendContent(limit(in, bodySize), response);          }        }      }    }  }