在Java中如何与不同的时区比较小时？ [英] Struggling with how to compare hours with different time zones in Java?

问题描述

我在数据库中有两个表示公司工作时间的日期对象。

I have 2 date object in the database that represent the company's working hours.

我只需要小时，但是我必须保存日期。它看起来像这样：

I only need the hours but since I have to save date. it appears like this:

Date companyWorkStartHour; 
Date companyWorkEndHour;

开始时间：12-12-2001-13：00：00
完成时间： 12-12-2001-18：00：00

start hours: 12-12-2001-13:00:00 finish hours: 12-12-2001-18:00:00

我有公司和用户的时区。 （我的服务器可能在另一个时区）。

I have the timezone of the company and of the user. (my server may be in another timezone).

TimeZone userTimeZone;
TimeZone companyTimeZone;

我需要检查用户的当前时间（考虑他的时区）是否在公司工作时间考虑公司的时区）。

I need to check if the user's current time (considering his timezone) is within the company working hours (considering the company's time zone).

我该怎么办？

推荐答案

java.util .Date 类是一个容器，自1970年1月1日00:00:00 UTC起，保存若干毫秒。注意， Date 类不知道关于时区的任何。

The java.util.Date class is a container that holds a number of milliseconds since 1 January 1970, 00:00:00 UTC. Note that class Date doesn't know anyting about timezones. Use class Calendar if you need to work with timezones.

日期不适合持有一个没有日期的小时数（例如13:00或18:00）。它不是为了这个目的，所以如果你尝试使用它，像你似乎在做，你会遇到一些问题，你的解决方案不会优雅。

Class Date is not really suited for holding an hour number (for example 13:00 or 18:00) without a date. It's simply not made for that purpose, so if you try to use it like that, as you seem to be doing, you'll run into a number of problems and your solution won't be elegant.

如果你忘记使用 Date 类来存储工作时间并使用整数，这将会更简单：

If you forget about using class Date to store the working hours and just use integers, this will be much simpler:

Date userDate = ...;
TimeZone userTimeZone = ...;

int companyWorkStartHour = 13;
int companyWorkEndHour = 18;

Calendar cal = Calendar.getInstance();
cal.setTime(userDate);
cal.setTimeZone(userTimeZone);

int hour = cal.get(Calendar.HOUR_OF_DAY);
boolean withinCompanyHours = (hour >= companyWorkStartHour && hour < companyWorkEndHour);

如果你还想花几分钟：

int companyWorkStart = 1300;
int companyWorkEnd = 1830;

int time = cal.get(Calendar.HOUR_OF_DAY) * 100 + cal.get(Calendar.MINUTE);
boolean withinCompanyHours = (time >= companyWorkStart && time < companyWorkEnd);

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