生成ABCD字母

for (int j = 0; j < size; j++) {
    
   originalPlatformOrderNo + ToolUtil.getLetterSuffix(j));
}

public static String getLetterSuffix(int num) {
    StringBuilder result = new StringBuilder();
    int quotient, remainder;
    quotient = num;
    while (quotient >= 0) {
        remainder = quotient % 26;
        result.insert(0, (char) (remainder + 65));
        quotient = (int) Math.floor(quotient / 26) - 1;
    }
    return result.toString();
}