Java LocalDate 输入验证

Question

被这个问题困扰了一段时间，希望得到一些意见。我想验证用户输入的日期，以便我可以使用 LocalDate 对象执行计算。但是，当输入有效日期时，返回的日期是前一个无效日期，这会引发异常并崩溃。我错过了什么或做错了什么。

public static void main(String[] args) {            
    Scanner sc = new Scanner(System.in);

    // Accept two dates from the user and return the number of days between the two dates
    numDaysBetween(sc); // calls to the inputDate are inside    

    sc.close();     

} // end main   

public static int[] inputDate(Scanner sc) {     
    System.out.print("Enter Date - In format dd/mm/yyyy: ");        

    while(!sc.hasNext("([0-9]{2})/([0-9]{2})/([0-9]){4}")) {
        System.out.print("That's not a valid date. Enter the date again: ");
        sc.nextLine();                 
    } // end while      
    String dateAsString = sc.nextLine();
    String[] dateArr = dateAsString.split("/");

    int[] dateArrInt = Arrays.asList(dateArr)
            .stream()
            .mapToInt(Integer::parseInt)
            .toArray();
    System.out.println(Arrays.toString(dateArrInt));
    try {
        //LocalDate date = LocalDate.of(dateArrInt[2], dateArrInt[1], dateArrInt[0]);
        LocalDate d = LocalDate.of(Integer.parseInt(dateArr[2]), Integer.parseInt(dateArr[1]), Integer.parseInt(dateArr[0]));
        //System.out.println(d.getDayOfMonth() + "/" + d.getMonthValue() + "/" + d.getYear() );

    } catch(DateTimeException e) {                  
        System.out.print(e.getMessage() + "\n");    
        inputDate(sc);

    } // end catch

    return dateArrInt;
} // end inputDate()

Answer 1

从字符串获取本地日期的正确方法是使用 DateTimeFormatter

    String str = "24/09/2017";
    DateTimeFormatter dt = DateTimeFormatter.ofPattern("dd/MM/yyyy");
    LocalDate date = LocalDate.parse(str, dt);