设置字符串格式时发生java FormatFlagsTransversionMismatchException异常

Question

我在程序中进行除法，并将结果打印到屏幕上。运行程序时没有问题，但当我尝试启动单元测试时，会收到以下错误：

java.util.FormatFlagsConversionMismatchException: Conversion = s, Flags = 0

在以下行：

String underscoreToResult = String.format("%" + (i - 2) + "s", "_");

下面我提供了与此方法相关的所有代码：

private StringBuilder bodyOfMethodCalculateDivisionWhenDividentLessThanDivisor(StringBuilder result, Integer reminderInInteger, int divisor, int divident, Integer divisorMuplipliedByQuotient,
                                                                               StringBuilder lastReminder, int i) {

    String underscoreToResult = String.format("%" + (i - 2) + "s", "_");
    String resultedReminder = reminderInInteger.toString();
    result.append(underscoreToResult).append(resultedReminder).append("\n");
    String multiply = String.format("%" + (i + 2) + "d", divisorMultipliedByQuontient(divisorMuplipliedByQuotient, divisor, reminderInInteger));
    result.append(multiply).append("\n");

    if (divident < divisor) {
        printLastNumber(lastReminder, reminderInInteger, multiply);
    }
    Integer tab = resultedReminder.length() - calculateAmountOfDigits(divisorMultipliedByQuontient(divisorMuplipliedByQuotient, divisor, reminderInInteger));
    String drawDashes = String.format("%" + (i + 2) + "s", createDivisor(divisorMultipliedByQuontient(divisorMuplipliedByQuotient, divisor, reminderInInteger), tab));
    result.append(drawDashes).append("\n");
    return result;
}

Answer 1

方法String.format("%Ns", "_");需要N>；0

由于您使用的是String.format("%" + (i - 2) + "s", "_");，因此需要确保单元测试始终使用i >= 3运行，以便出现任何异常