public static Variant selectVariant(ContainerRequest r, List<Variant> variants) {
LinkedList<VariantHolder> vhs = getVariantHolderList(variants);
Set<String> vary = new HashSet<String>();
vhs = selectVariants(vhs, HttpHelper.getAccept(r), MEDIA_TYPE_DC, vary);
vhs = selectVariants(vhs, HttpHelper.getAcceptLanguage(r), LANGUAGE_TAG_DC, vary);
vhs = selectVariants(vhs, HttpHelper.getAcceptCharset(r), CHARSET_DC, vary);
vhs = selectVariants(vhs, HttpHelper.getAcceptEncoding(r), ENCODING_DC, vary);
if (vhs.isEmpty()) {
return null;
} else {
StringBuilder varyHeader = new StringBuilder();
for (String v : vary) {
if (varyHeader.length() > 0) {
varyHeader.append(',');
}
varyHeader.append(v);
}
r.getProperties().put(ContainerRequest.VARY_HEADER, varyHeader.toString());
return vhs.iterator().next().v;
}
}