Java SimpleDateFormat引发ParseException:Windows上无法解析的日期，但Mac上没有 [英] Java SimpleDateFormat throwing ParseException: Unparseable date on Windows but not on Mac

问题描述

我有以下方法:

    public static Date convertFromWowInterface(String wowinterfaceFormat){
        Date date = null;
        try {
            SimpleDateFormat dateFormat = new SimpleDateFormat("MM-dd-yy hh:mm a");
            date = dateFormat.parse(wowinterfaceFormat);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return date;
    }

传入的字符串的格式为:

The string being passed in is of the format:

"08-11-19 07:00 AM"

显然没有引号.现在上面的方法在我的Mac上可以正常工作，但是当我的某些用户在Windows上使用该程序时，他们会收到异常:

without the quotes obviously. Now the above method works just fine on my mac, however when some of my users use the program (on Windows) they get the exception:

java.text.ParseException: Unparseable date: "08-11-19 07:00 AM"
        at java.base/java.text.DateFormat.parse(DateFormat.java:395)

操作系统在这里是否有所作为?还是还有其他东西在玩?据我所知，SimpleDateFormat与输入字符串完全匹配吗?

Does the OS make a difference here? Or is there something else at play? As far as I can tell the SimpleDateFormat match the input string exactly?

推荐答案

当我切换到其他语言环境时，我可以重现该问题.

I can reproduce the problem when I switch to a different locale.

这是我的演示程序:

import java.util.*;
import java.text.*;

public class YourCode {
    public static void main(String[] args) throws Exception {
        for (String a : args) {
            SimpleDateFormat dateFormat = new SimpleDateFormat("MM-dd-yy hh:mm a");
            Date d = dateFormat.parse(a);
            System.out.println(d);
        }
    }
}

当我在美国英语语言环境下运行它时，它会起作用:

It works, when I run it under US English locale:

robert@saaz:~$ LC_ALL="en_US.UTF-8" java YourCode "08-11-19 07:00 AM" 
Sun Aug 11 07:00:00 CDT 2019

当我切换到例如德国语言环境时，会看到一个例外，该语言使用24小时制，而不是AM/PM.

I get the exception you see when I switch to e.g., German locale, which uses 24h time, not AM/PM.

robert@saaz:~$ LC_ALL="de_DE.UTF-8" java YourCode "08-11-19 07:00 AM" 
Exception in thread "main" java.text.ParseException: Unparseable date: "08-11-19 07:00 AM"
    at java.base/java.text.DateFormat.parse(DateFormat.java:395)
    at YourCode.main(YourCode.java:8)

要解决此问题，请在创建 SimpleDateFormat 时指定语言环境.更改

To get around this, specify the locale when you create the SimpleDateFormat. Change

SimpleDateFormat dateFormat = new SimpleDateFormat("MM-dd-yy hh:mm a");

到

SimpleDateFormat dateFormat = new SimpleDateFormat("MM-dd-yy hh:mm a", Locale.US);

这篇关于Java SimpleDateFormat引发ParseException:Windows上无法解析的日期，但Mac上没有的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！