努力与Java中的不同时区比较小时数？ [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代表公司工作时间的日期对象。

我只需要几个小时，但是由于我必须保存日期。看起来像这样：

  Date companyWorkStartHour; 
 Date companyWorkEndHour; 
  

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

我有公司和用户的时区。 （我的服务器可能位于另一个时区）。

  TimeZone userTimeZone; 
 TimeZone companyTimeZone; 
  

我需要检查用户当前的时间（考虑到他的时区）在公司工作时间内考虑到公司的时区）。

我该怎么做？我用Java日历挣扎了一个多星期，没有成功！

解决方案

java.util .Date class是从1970年1月1日00:00:00 UTC起持续数毫秒的容器。请注意，类 Date 不知道有关时区的信息。如果您需要使用时区，请使用课程 Calendar 。 （编辑：2017年1月19日：如果您使用Java 8，请在包 java.time ）中使用新的日期和时间API。 / p>

类日期不适合持有小时号（例如13:00或18:00），没有一个约会。这完全不是为了这个目的，所以如果你这样尝试使用它，就像你似乎正在做的那样，你会遇到一些问题，你的解决方案不会很优雅。

如果您忘记使用类 Date 来存储工作时间并使用整数，这将会简单得多：

  Date userDate = ...; 
 TimeZone userTimeZone = ...; 
 
 int companyWorkStartHour = 13; 
 int companyWorkEndHour = 18; 
 
日历cal = Calendar.getInstance（）; 
 cal.setTime（userDate）; 
 cal.setTimeZone（userTimeZone）; 
 
 int hour = cal.get（Calendar.HOUR_OF_DAY）; 
 boolean withinCompanyHours =（hour> = companyWorkStartHour&&& hour< companyWorkEndHour）; 
  

如果你也想花几分钟（不只是几个小时），你可以做这样的事情：

  int companyWorkStart = 1300; 
 int companyWorkEnd = 1830; 
 
 int time = cal.get（Calendar.HOUR_OF_DAY）* 100 + cal.get（Calendar.MINUTE）; 
 boolean inCompanyHours =（time> = companyWorkStart&& time< companyWorkEnd）; 
  

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

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

Date companyWorkStartHour; 
Date companyWorkEndHour;

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

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

TimeZone userTimeZone;
TimeZone companyTimeZone;

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).

How can I do it? I am struggling for over a week with Java calendar and with no success!

解决方案

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. (edit 19-Jan-2017: if you are using Java 8, use the new date and time API in package java.time).

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.

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);

If you also want to take minutes (not just hours) into account, you could do something like this:

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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