code: static String toUnixStylePath(String absolutePath) {
          if (StringUtils.isEmpty(absolutePath)) {
              throw new IllegalStateException("empty path given");
          }
          if (absolutePath.startsWith("/")) {
              return absolutePath;
          } else if (absolutePath.length()>=2 && Character.isLetter(absolutePath.charAt(0)) && ':' == absolutePath.charAt(1) && '\\' == absolutePath.charAt(2)) {
              char driveLetter = Character.toLowerCase(absolutePath.charAt(0));
              String drivePath = StringUtils.substringAfter(absolutePath, ":");
              String drivePathUnixStyle = drivePath.replace('\\', '/');
              return "/"+driveLetter+drivePathUnixStyle;
          } else {
              throw new IllegalStateException(String.format("unable to convert path %s", absolutePath));
          }
      }
docs: Convert any absolute path (no matter Unix or Windows style) to Unix style
  path compatible to docker volume mount from syntax.