code: public static String normalizePath(String path) {
          if (path == null) {
              return null;
          }
  
          path = path.trim();
  
          if (path.isEmpty()) {
              return "";
          }
  
          path = path.replace("\\", "/");
  
          if (!path.startsWith("/")) {
              path = "/" + path;
          }
          return path;
      }
docs: Normalize the path, for example, the context root path. The rules are:
  1. Return null if the path is null
  2. Return "" if the path is an empty string.
  3. Replace all "\" by "/" in the path string.
  4. Add "/" if the path does not start with "/"
  
  @param path
  @return the normalized path string.