# File lib/jpmobile/filter.rb, line 71
    def filter(str, from, to)
      str = str.clone

      # 一度UTF-8に変換
      before_encoding = nil
      if str.respond_to?(:force_encoding)
        before_encoding = str.encoding
        str.force_encoding("UTF-8")
      end

      from.each_with_index do |int, i|
        str.gsub!(int, to[i])
      end

      # 元に戻す
      if before_encoding
        str.force_encoding(before_encoding)
      end

      str
    end