In Rails, how do I determine if two URLs are equal?
def is_same_controller_and_action?(url1, url2)
  hash_url1 = Rails.application.routes.recognize_path(url1)
  hash_url2 = Rails.application.routes.recognize_path(url2)

  [:controller, :action].each do |key|
    return false if hash_url1[key] != hash_url2[key]
  end

  return true
end

def to_canonical(url)
  uri = Addressable::URI.parse(url)
  uri.scheme = "http" if uri.scheme.blank?
  host = uri.host.sub(/www./, '') if uri.host.present?
  path = (uri.path.present? && uri.host.blank?) ? uri.path.sub(/www./, '') : uri.path
  uri.scheme.to_s + "://" + host.to_s + path.to_s
rescue Addressable::URI::InvalidURIError
  nil
rescue URI::Error
  nil
end

> to_canonical('www.example.com') => 'http://example.com'
> to_canonical('http://example.com') => 'http://example.com'

uri = Addressable::URI.parse("http://www.詹姆斯.com/")
uri.normalize
#=> #<Addressable::URI:0xc9a4c8 URI:http://www.xn--8ws00zhy3a.com/>