我正在开发和Android应用程序，我需要计算两次之间的差异。我需要计算24小时的时差，以及两天的时间差（例如今天下午5点到明天上午9点）。
我尝试了以下代码，计算仅适用于24小时的差异，
String dateStart = "08:00:00";
String dateStop = "13:00:00";
//HH converts hour in 24 hours format (0-23), day calculation
SimpleDateFormat format = new SimpleDateFormat("HH:mm:ss");
Date d1 = null;
Date d2 = null;
try
{
d1 = format.parse(dateStart);
d2 = format.parse(dateStop);
//in milliseconds
long diff = d2.getTime() - d1.getTime();
long diffHours = diff / (60 * 60 * 1000) % 24;
Log.e("test",diffHours + " hours, ");
}
catch (Exception e)
{
// TODO: handle exception
}
先生，您可以轻松使用java功能。 long difference = date2.getTime() - date1.getTime();看看这个link这会对你有所帮助。
找到适当时差的正确方法：
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("HH:mm");
Date startDate = simpleDateFormat.parse("22:00");
Date endDate = simpleDateFormat.parse("07:00");
long difference = endDate.getTime() - startDate.getTime();
if(difference<0)
{
Date dateMax = simpleDateFormat.parse("24:00");
Date dateMin = simpleDateFormat.parse("00:00");
difference=(dateMax.getTime() -startDate.getTime() )+(endDate.getTime()-dateMin.getTime());
}
int days = (int) (difference / (1000*60*60*24));
int hours = (int) ((difference - (1000*60*60*24*days)) / (1000*60*60));
int min = (int) (difference - (1000*60*60*24*days) - (1000*60*60*hours)) / (1000*60);
Log.i("log_tag","Hours: "+hours+", Mins: "+min);
结果将是：小时：9，分钟：0
ChronoUnit.HOURS.between(
LocalTime.parse( "08:00:00" ) ,
LocalTime.parse( "13:00:00" )
)
5
…要么…
ChronoUnit.HOURS.between(
ZonedDateTime.of(
LocalDate.of( 2017 , Month.JANUARY , 23 ) ,
LocalTime.parse( "08:00:00" ) ,
ZoneId.of( "America/Montreal" )
) ,
ZonedDateTime.of(
LocalDate.of( 2017 , Month.JANUARY , 25 ) ,
LocalTime.parse( "13:00:00" ) ,
ZoneId.of( "America/Montreal" )
)
)
53
现代方法使用java.time类。
LocalTimeLocalTime类表示没有日期且没有时区的时间。
LocalTime start = LocalTime.parse( "08:00:00" ) ;
LocalTime stop = LocalTime.parse( "13:00:00" ) ;
Duration获取Duration对象来表示时间跨度。
Duration d = Duration.between( start , stop ) ;
ChronoUnit若干小时，请使用ChronoUnit。
long hours = ChronoUnit.HOURS.between( start , stop ) ;
对于Android，请参阅ThreeTen-Backport和ThreeTenABP项目。见下面的子弹。
ZonedDateTime如果您想跨越几天，经过午夜，您必须指定日期和时区。
时区对于确定日期至关重要。对于任何给定的时刻，日期在全球范围内因地区而异。例如，在Paris France午夜过后几分钟是新的一天，而在Montréal Québec仍然是“昨天”。
以proper time zone name的格式指定continent/region，例如America/Montreal，Africa/Casablanca或Pacific/Auckland。切勿使用诸如EST或IST之类的3-4字母缩写，因为它们不是真正的时区，不是标准化的，甚至不是唯一的（！）。
ZoneId z = ZoneId.of( "America/Montreal" ) ;
ZonedDateTime start = ZonedDateTime.of(
LocalDate.of( 2017 , Month.JANUARY , 23 ) ,
LocalTime.parse( "08:00:00" ) ,
z
) ;
ZonedDateTime stop = ZonedDateTime.of(
LocalDate.of( 2017 , Month.JANUARY , 25 ) ,
LocalTime.parse( "13:00:00" ) ,
z
) ;
long hours = ChronoUnit.HOURS.between( start , stop ) ;
看到这个code run live at IdeOne.com。
53
java.time框架内置于Java 8及更高版本中。这些类取代了麻烦的旧legacy日期时间类，如java.util.Date，Calendar和SimpleDateFormat。
现在在Joda-Time的maintenance mode项目建议迁移到java.time班。
要了解更多信息，请参阅Oracle Tutorial。并搜索Stack Overflow以获取许多示例和解释。规格是JSR 310。
从哪里获取java.time类？
如果您确定第二天上午9点可以添加一天并计算差异，您也可以尝试这样的事情：
String string1 = "05:00:00 PM";
Date time1 = new SimpleDateFormat("HH:mm:ss aa").parse(string1);
Calendar calendar1 = Calendar.getInstance();
calendar1.setTime(time1);
String string2 = "09:00:00 AM";
Date time2 = new SimpleDateFormat("HH:mm:ss aa").parse(string2);
Calendar calendar2 = Calendar.getInstance();
calendar2.setTime(time2);
calendar2.add(Calendar.DATE, 1);
Date x = calendar1.getTime();
Date xy = calendar2.getTime();
long diff = x.getTime() - xy.getTime();
diffMinutes = diff / (60 * 1000);
float diffHours = diffMinutes / 60;
System.out.println("diff hours" + diffHours);
我这样做了：
Date time1 = new SimpleDateFormat("HH:mm:ss aa").parse(string1);
Calendar calendar1 = Calendar.getInstance();
calendar1.setTime(time1);
Date time2 = new SimpleDateFormat("HH:mm:ss aa").parse(string2);
Calendar calendar2 = Calendar.getInstance();
calendar2.setTime(time2);
if(calendar2.get(Calendar.AM_PM) == 1 && calendar1.get(Calendar.AM_PM) == 0) {
calendar2.add(Calendar.DATE, 1);
}
long diff = calendar1.getTimeInMillis() - calendar2.getTimeInMillis()
这将有助于找到全天候的时间差异。
Try simple piece of code using For 24 hour time
StartTime = "10:00";
EndTime = "13:00";
here starthour=10 and end hour=13
if(TextUtils.isEmpty(txtDate.getText().toString())||TextUtils.isEmpty(txtDate1.getText().toString())||TextUtils.isEmpty(txtTime.getText().toString())||TextUtils.isEmpty(txtTime1.getText().toString()))
{
Toast.makeText(getApplicationContext(), "Date/Time fields cannot be blank", Toast.LENGTH_SHORT).show();
}
else {
if (starthour > endhour) {
Toast.makeText(getApplicationContext(), "Start Time Should Be Less Than End Time", Toast.LENGTH_SHORT).show();
} else if (starthour == endhour) {
if (startmin > endmin) {
Toast.makeText(getApplicationContext(), "Start Time Should Be Less Than End Time", Toast.LENGTH_SHORT).show();
}
else{
tvalid = "True";
}
} else {
// Toast.makeText(getApplicationContext(),"Sucess"+(endhour-starthour)+(endmin-startmin),Toast.LENGTH_SHORT).show();
tvalid = "True";
}
}
same for date also