Strings { public static boolean isNotEmpty(final String s) { return !isEmpty(s); } private  Strings(); static boolean isNull(final String s); static boolean isEmpty(final String s); static boolean isNotEmpty(final String s); static boolean isBlank(final String s); static String trim(final String s); static String trimToNull(final String s); static String trimToEmpty(final String s); static String toLowerCase(final String s);  }
@Test public void testIsNotEmpty() { final String nullString = null; final String emptyString = ""; final String blankString = " "; final String string = "a"; assertThat(Strings.isNotEmpty(nullString), is(false)); assertThat(Strings.isNotEmpty(emptyString), is(false)); assertThat(Strings.isNotEmpty(blankString), is(true)); assertThat(Strings.isNotEmpty(string), is(true)); }