Question

请帮我将hexstring转换为base64

这里是我得到异常的地方

 String hexString = "bf940165bcc3bca12321a5cc4c753220129337b48ad129d880f718d147a2cd1bfa79de92239ef1bc06c2f05886b0cd5d";

private static String ConvertHexStringToBase64(String hexString) {
    System.out.println(hexString);
    if ((hexString.length()) % 2 > 0)
        throw new NumberFormatException("Input string was not in a correct format.");
     byte[] buffer = new byte[hexString.length() / 2];
        int i = 0;
        while (i < hexString.length())
        {
            buffer[i / 2] = Byte.parseByte(hexString.substring(i, 2));
            i += 2;
        }
        System.out.println("hexSring"+hexString+"afterconverttobase64"+Base64.encodeBase64String(buffer));
        return Base64.encodeBase64String(buffer);

}

我在这里得到一个例外:: bf940165bcc3bca12321a5cc4c753220129337b48ad129d880f718d147a2cd1bfa79de92239ef1bc06c2f05886b0cd5d Exception in thread "main" java.lang.NumberFormatException: For input string: "bf" at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48) at java.lang.Integer.parseInt(Integer.java:449) at java.lang.Byte.parseByte(Byte.java:151) at java.lang.Byte.parseByte(Byte.java:108) at com.motorola.gst.DecryptTest3.ConvertHexStringToBase64(DecryptTest3.java:38) at com.motorola.gst.DecryptTest3.main(DecryptTest3.java:16)

Answer 1

首先，您必须在parseByte方法中指定指定基数（在您的情况下为16）以避免numberFormat异常：

 buffer[i / 2] = Byte.parseByte(hexString.substring(i, 2),16);

然而，您的代码似乎已损坏，请查看更正后的代码：

     if ((hexString.length()) % 2 > 0)
          throw new NumberFormatException("Input string was not in a correct format.");
       int[] buffer = new int[hexString.length() / 2];
          int i = 2;
          while (i < hexString.length())
          {
              buffer[i / 2] = Integer.parseInt(hexString.substring(i, i + 2),16);
              i += 2;
          }

您的循环错误，您必须解析为Integer，因为您的输入字符串中有一些值溢出字节功能...

如果你需要byte，你可以用这种方式将解析的int转换为byte：

       byte[] buffer = new byte[hexString.length() / 2];
          int i = 2;
          while (i < hexString.length())
          {
              buffer[i / 2] = (byte)Integer.parseInt(hexString.substring(i, i + 2),16);
              i += 2;
          }

Answer 2

找到一个类似的解决方案，认为分享可能会很好：

    public static string convertHexToBase64String(String hexString)
    {
        string base64 = "";

        //--Important: remove "0x" groups from hexidecimal string--
        hexString = hexString.Replace("0x", "");

        byte[] buffer = new byte[hexString.Length / 2];

        for (int i = 0; i < hexString.Length; i++)
        {
            try
            {
                buffer[i / 2] = Convert.ToByte(Convert.ToInt32(hexString.Substring(i, 2), 16));
            }
            catch (Exception ex) { }
            i += 1;
        }

        base64 = Convert.ToBase64String(buffer);

        return base64;
    }

希望它可以帮助别人。

将十六进制字符串转换为base64

2 个答案: