java - 格式化字符串时出现 FormatFlagsConversionMismatchException

Question

我在我的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，但是当我尝试启动单元测试时收到以下错误:

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", "_");您需要确保单元测试始终使用 i >= 3 运行以便引发任何异常。