code: public Permission getPermission() throws IOException {
          if (permission == null) {
              String decodedPath = ParseUtil.decode(url.getPath());
              if (File.separatorChar == '/') {
                  permission = new FilePermission(decodedPath, "read");
              } else {
                  permission = new FilePermission(
                          decodedPath.replace('/',File.separatorChar), "read");
              }
          }
          return permission;
      }
docs: /* since getOutputStream isn't supported, only read permission is
  relevant