private static void addIf(final StringBuilder sb, final String s) {
        if (!StringUtils.isBlank(s)) {
            if (!sb.toString().isEmpty()) {
                sb.append(" - ");
            }
            sb.append(s);
        }
    }
Tries to read metadata from given stream, assuming it is an image data stream

@param description describes the stream. Used for logging in case of errors
@param imageStream image data stream
@param closeAfter  if true, stream is closed after read
@return Metadata read, or null if metadata could not be read
main/src/main/java/cgeo/geocaching/utils/MetadataUtils.java