TextUtils { public static boolean isEmpty(final CharSequence s) { if (s == null) { return true; } return s.length() == 0; } private  TextUtils(); static boolean isEmpty(final CharSequence s); static boolean isBlank(final CharSequence s); static boolean containsBlanks(final CharSequence s); static String toHexString(final byte[] bytes);  }
@Test public void testTextEmpty() { Assert.assertTrue(TextUtils.isEmpty(null)); Assert.assertTrue(TextUtils.isEmpty("")); Assert.assertFalse(TextUtils.isEmpty("\t")); }