public static String truncateUtf8(String str, int maxBytes) {
		Charset charset = StandardCharsets.UTF_8;
		//UTF-8编码单个字符最大长度4
		return truncateByByteLength(str, charset, maxBytes, 4, true);
	}
@Test
	public void truncateUtf8Test2() {
		final String str = "这是This一";
		final String ret = StrUtil.truncateUtf8(str, 13);
		assertEquals("这是This一", ret);
	}