Convert a decoded path to a canonical form.
<p>
All instances of "." and ".." are factored out.
</p>
<p>
Null is returned if the path tries to .. above its root.
</p>
@param path the path to convert, decoded, with path separators '/' and no queries.
@return the canonical path, or null if path traversal above root.
Convert a decoded path to a canonical form. <p> All instances of "." and ".." are factored out. </p> <p> Null is returned if the path tries to .. above its root. </p>
@param path the path to convert, decoded, with path separators '/' and no queries. @return the canonical path, or null if path traversal above root.