protected String getFedoraResourceURI(String res) {
        // strip off info URI part if present
        String strippedRes;
        if (res.startsWith(Constants.FEDORA.uri)) {
            strippedRes = res.substring(Constants.FEDORA.uri.length());
        } else {
            strippedRes = res;
        }
        // split into pid + datastream (if present), validate PID and then recombine datastream back in using URI form of PID
        String parts[] = strippedRes.split("/");
        PID pid;
        try {
            pid = new PID(parts[0]);
        } catch (MalformedPIDException e1) {
            logger.warn("Invalid Fedora resource identifier: {}. PID part of URI is malformed", res);
            return null;
        }

        String resURI;
        if (parts.length == 1) {
            resURI = pid.toURI();
        } else if (parts.length == 2) {
            resURI = pid.toURI() + "/" + parts[1]; // add datastream ID back
        } else {
            logger.warn("Invalid Fedora resource identifier: {}. Should be pid or datastream (URI form optional", res);
            return null;
        }
        return resURI;
    }
protected String getFedoraResourceURI ( String res ) { String strippedRes ; if ( res . startsWith ( Constants . FEDORA . uri ) ) { strippedRes = res . substring ( Constants . FEDORA . uri . length ( ) ) ; } else { strippedRes = res ; } String parts [ ] = strippedRes . split ( "/" ) ; PID pid ; try { pid = new PID ( parts [ 0 ] ) ; } catch ( MalformedPIDException e1 ) { logger . warn ( "Invalid Fedora resource identifier: {}. PID part of URI is malformed" , res ) ; return null ; } String resURI ; if ( parts . length == 1 ) { resURI = pid . toURI ( ) ; } else if ( parts . length == 2 ) { resURI = pid . toURI ( ) + "/" + parts [ 1 ] ; } else { logger . warn ( "Invalid Fedora resource identifier: {}. Should be pid or datastream (URI form optional" , res ) ; return null ; } return resURI ; }
given either a ns:pid/ds identifier or an info:fedora/ URI form of the same
return the URI form, validating the PID part.  Returns null if the argument
was invalid/could not be validated/converted

@param res identifier for fedora resource
@return URI form