读取IC Track2 C跟java实现对比！

// Read Track 2 Equivalent Data
    bReadTrack2 = FALSE;
    memset(sTemp, 0, sizeof(sTemp));

    iRet = emv_get_data_element("\x57", 1, &iLength, sTemp);
    iErrNo = iRet?errno:0;
    if( iErrNo==EMV_RET_SUCCESS )
    {
        bReadTrack2 = TRUE;
        BcdToAsc0(PosCom.szTrack2, sTemp, iLength*2);
        RemoveTailChars(PosCom.szTrack2, 'F');	// erase padded 'F' chars
        for(i=0; PosCom.szTrack2[i]!='\0'; i++)		// convert 'D' to '='
        {
            if( PosCom.szTrack2[i]=='D' )
            {
                PosCom.szTrack2[i] = '=';
                break;
            }
        }
    }

void RemoveTailChars(uint8_t *pszString, uint8_t ucRemove)
{
    int	i, iLen;

    iLen = strlen((char *)pszString);
    for(i=iLen-1; i>0; i--)
    {
        if( pszString[i]!=ucRemove )
        {
            break;
        }
        pszString[i] = 0;
    }
}

JAVA实现

         
        byte[] track2 = Arrays.copyOfRange(data, 2, 2 + data[1] & 0xFF);
        int track2Length = data[1] & 0xFF;
        String trackContent = tools.hexString(track2);
        // 删除结尾的 'F'，替换 'D' 为 '='
        String formattedTrack2 = trackContent.replaceAll("F*$", "").replace('D', '=');
        String finalTrack2 = track2Length + formattedTrack2;
        card.setTrack2(finalTrack2);