java - 在 Java 中抛出自定义 NumberFormatException

Question

在将字符串月份转换为整数时，我试图抛出自己的 NumberFormatException。不确定如何抛出异常。任何帮助，将不胜感激。我需要在这部分代码之前添加一个try-catch吗？我的代码的另一部分已经有一个。

// sets the month as a string
mm = date.substring(0, (date.indexOf("/")));
// sets the day as a string
dd = date.substring((date.indexOf("/")) + 1, (date.lastIndexOf("/")));
// sets the year as a string
yyyy= date.substring((date.lastIndexOf("/"))+1, (date.length()));
// converts the month to an integer
intmm = Integer.parseInt(mm);
/*throw new NumberFormatException("The month entered, " + mm+ is invalid.");*/
// converts the day to an integer
intdd = Integer.parseInt(dd);
/* throw new NumberFormatException("The day entered, " + dd + " is invalid.");*/
// converts the year to an integer
intyyyy = Integer.parseInt(yyyy);
/*throw new NumberFormatException("The yearentered, " + yyyy + " is invalid.");*/

Answer 1

像这样:

try {
    intmm = Integer.parseInt(mm);
catch (NumberFormatException nfe) {
    throw new NumberFormatException("The month entered, " + mm+ " is invalid.");
}

或者，更好一点:

try {
    intmm = Integer.parseInt(mm);
catch (NumberFormatException nfe) {
    throw new IllegalArgumentException("The month entered, " + mm+ " is invalid.", nfe);
}

编辑:既然您已经更新了帖子，您实际上似乎需要的是类似parse(String) 的东西。简单日期格式