anonymous GET all others to be authentificated

Hi Guys I am stuck with an issue here, I have a web page that I need to allow anonymous views but not post/put/etc.
Is that posible with nginx ? could this be a webdav thing?

Currently I have this config, which is not really working, it is asking for a password all the time.

location /java/stable {
root /storage/docs/java/stable;
autoindex on;
dav_methods PUT DELETE MKCOL COPY MOVE;
dav_ext_methods PROPFIND OPTIONS;
create_full_put_path on;
dav_access group:rw all:r;
auth_basic "Restricted";
auth_basic_user_file /srv/.webdav_htpasswd;