PathUtils { public static String ensureStartingSlash(String path) { Objects.requireNonNull(path, "path must not be null"); return "".equals(path) || path.charAt(0) != '/' ? ("/" + path) : path; }  static String noStartingSlash(String path); static boolean hasStartingSlash(String path); static String noPrefix(String path, String prefix); static String ensureStartingSlash(String path); static String ensureEndingSlash(String path); static String ensureNotEndingSlash(String path); static String normalizePath(String path);  }
@Test public void ensureStartingSlash() { assertThat(PathUtils.ensureStartingSlash("foo"), is("/foo")); assertThat(PathUtils.ensureStartingSlash("/foo"), is("/foo")); assertThat(PathUtils.ensureStartingSlash("/foo/"), is("/foo/")); assertThat(PathUtils.ensureStartingSlash("/"), is("/")); assertThat(PathUtils.ensureStartingSlash(""), is("/")); }