code: public byte[] getCacheContent(String rfsName) {
  
          try {
              File f = new File(rfsName);
              if (f.exists()) {
                  long age = f.lastModified();
                  if ((System.currentTimeMillis() - age) > 3600000) {
                      // file has not been touched for 1 hour, touch the file with the current date
                      f.setLastModified(System.currentTimeMillis());
                  }
                  return CmsFileUtil.readFile(f);
              }
          } catch (IOException e) {
              // unable to read content
              LOG.debug("Unable to read file " + rfsName, e);
          }
          return null;
      }
docs: Returns the content of the requested file in the disk cache, or <code>null</code> if the
  file is not found in the cache, or is found but outdated.<p>
  
  @param rfsName the file RFS name to look up in the cache
  
  @return the content of the requested file in the disk cache, or <code>null</code>