从用户那里获取日期输入并将其另存为Java中的日期 [英] Take date input from user and save it as date in java

问题描述

我正在尝试以(dd/mm/yy)格式接收用户的输入，将其保存为相同格式，然后将其与getter，setter一起传递给另一个类.我已经尝试过这种方式:

I'm trying to take input from user in (dd/mm/yy) format, save it in same format and pass it with getter, setter to another class. I have tried this way:

这是我尝试过的:

public static void main(String[] args)
{
    Scanner input = new Scanner(System.in);
    SimpleDateFormat myFormat = new SimpleDateFormat("dd MM yyyy");
    Guest gstObject = new Guest();
    try {
        System.out.println("Enter check-in date (dd/mm/yy):");
        String cindate = input.next();
        Date date1 = myFormat.parse(cindate);
        gstObject.setIndate(date1);
    } catch (ParseException e) {
        e.printStackTrace();
    }
}

使用此代码，我在(27012017或27 01 2017)中输入内容时会遇到异常:

With this code I'm getting an exception when I give input in (27012017 or 27 01 2017):

java.text.ParseException: Unparseable date: "27"
  at java.text.DateFormat.parse(DateFormat.java:366)
  at edu.lfa.GuestArrayList.main(GuestArrayList.java:49)

请指出我犯了什么错误.

Please point out what mistake I have made.

推荐答案

其他答案解决了如何正确使用Scanner的问题.我将解决其他一些问题.

Other answers addressed how to use Scanner correctly. I'll address some other issues.

您正在使用麻烦的旧日期时间类(现在已遗留)，由java.time类取代.避免像瘟疫这样的java.util.Date类.

You are using troublesome old date-time classes, now legacy, supplanted by the java.time classes. Avoid the java.util.Date class like the Plague.

此外，您不恰当地尝试用date + time类表示仅日期的值.

Also, you are inappropriately trying to represent a date-only value with a date+time class.

相反，请使用java.time.LocalDate. LocalDate 类表示日期-仅值，没有时间和时区.

Instead, use java.time.LocalDate. The LocalDate class represents a date-only value without time-of-day and without time zone.

要解析用户的输入，请指定一种格式匹配方式，以完全匹配 用户的预期输入.

To parse the user's input, specify a formatting pattern to match exactly the expected input from your user.

DateTimeFormatter f = DateTimeFormatter.parse( "dd/mm/uuuu" );

解析用户输入.

LocalDate ld = LocalDate.parse( input , f );

在业务类Guest上，使成员变量的类型为LocalDate.

On your business class Guest, make the member variable of type LocalDate.

要保留LocalDate，您可以序列化为标准 ISO 8601 格式的文本.只需致电toString.

To persist the LocalDate, you can serialize to text in standard ISO 8601 format. Simply call toString.

String output = guest.getLocalDate().toString();

2017-01-23

2017-01-23

---

关于java.time

java.time 框架已内置在Java 8及更高版本中.这些类取代了麻烦的旧版日期时间类，例如 SimpleDateFormat .

---

About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

Joda-Time 项目，现在位于

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

要了解更多信息，请参见 Oracle教程.并在Stack Overflow中搜索许多示例和说明.规范为 JSR 310 .

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

在哪里获取java.time类?

Where to obtain the java.time classes?

• Java SE 8 和 SE 9 及更高版本
  • 内置.
  • 具有捆绑的实现的标准Java API的一部分.
  • Java 9添加了一些次要功能和修复.
  • Java SE 8 and SE 9 and later
    • Built-in.
    • Part of the standard Java API with a bundled implementation.
    • Java 9 adds some minor features and fixes.
    • 许多java.time功能都向后移植到Java 6& 7在> ThreeTen-Backport 中./li>
    • > ThreeTenABP 项目适应了<专门用于Android的em> ThreeTen-Backport (上面提到).
    • 请参阅 如何使用ThreeTenABP… .
    • The ThreeTenABP project adapts ThreeTen-Backport (mentioned above) for Android specifically.
    • See How to use ThreeTenABP….

    ThreeTen-Extra 项目使用其他类扩展了java.time.该项目为将来可能在java.time中添加内容提供了一个试验场.您可能会在这里找到一些有用的类，例如 Interval ， YearWeek ， YearQuarter 和更多.

    The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

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