code: public static byte[] sha256X16(String data, String encoding) {
  		byte[] bytes = sha256(data, encoding);
  		StringBuilder sha256StrBuff = new StringBuilder();
  		for (int i = 0; i < bytes.length; i++) {
  			if (Integer.toHexString(0xFF & bytes[i]).length() == 1) {
  				sha256StrBuff.append("0").append(
  						Integer.toHexString(0xFF & bytes[i]));
  			} else {
  				sha256StrBuff.append(Integer.toHexString(0xFF & bytes[i]));
  			}
  		}
  		try {
  			return sha256StrBuff.toString().getBytes(encoding);
  		} catch (UnsupportedEncodingException e) {
  			LogUtil.writeErrorLog(e.getMessage(), e);
  			return null;
  		}
  	}
docs: sha256计算后进行16进制转换
  
  @param data
  待计算的数据
  @param encoding
  编码
  @return 计算结果