Question

我有两个字符串变量，如StartTime和EndTime。我需要通过用StartTime减去EndTime来计算TotalTime。

StartTime和EndTime的格式如下：

StartTime = "08:00 AM";
EndTime = "04:00 PM";

小时和分钟格式的总时间。如何在Android中计算？

Answer 1

尝试以下代码。

SimpleDateFormat simpleDateFormat = new SimpleDateFormat("HH:mm a");
date1 = simpleDateFormat.parse("08:00 AM");
date2 = simpleDateFormat.parse("04:00 PM");

long difference = date2.getTime() - date1.getTime(); 
days = (int) (difference / (1000*60*60*24));  
hours = (int) ((difference - (1000*60*60*24*days)) / (1000*60*60)); 
min = (int) (difference - (1000*60*60*24*days) - (1000*60*60*hours)) / (1000*60);
hours = (hours < 0 ? -hours : hours);
Log.i("======= Hours"," :: "+hours);

输出 - 小时数：8

Answer 2

看一下DateFormat，你可以使用它来解析你的字符串，使用parse（String source）方法，你就可以轻松地操纵两个Dates对象来获得你想要的东西。

DateFormat df = DateFormat.getInstance();
Date date1 = df.parse(string1);
Date date2 = df.parse(string2);
long difference = date1.getTime() - date2.getTime();

days = (int) (difference / (1000*60*60*24));  
hours = (int) ((difference - (1000*60*60*24*days)) / (1000*60*60)); 
min = (int) (difference - (1000*60*60*24*days) - (1000*60*60*hours)) / (1000*60);

String diffHours = df.format(hours);

日期差异

Date myDate = new Date(difference);

显示日期：

String diff = df.format(myDate);

Answer 3

注意：更正了Chirag Raval提供的代码，因为在我们尝试从22:00到07:00找时间时，Chirag提供的代码存在一些问题。

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

Answer 4

我想贡献现代的答案。

java.time和ThreeTenABP

    DateTimeFormatter timeFormatter = DateTimeFormatter.ofPattern("hh:mm a", Locale.ENGLISH);

    String startTime = "08:00 AM";
    String endTime = "04:00 PM";

    LocalTime start = LocalTime.parse(startTime, timeFormatter);
    LocalTime end = LocalTime.parse(endTime, timeFormatter);

    Duration diff = Duration.between(start, end);

    long hours = diff.toHours();
    long minutes = diff.minusHours(hours).toMinutes();
    String totalTimeString = String.format("%02d:%02d", hours, minutes);
    System.out.println("TotalTime in Hours and Mins Format is " + totalTimeString);

此代码段的输出为：

小时和分钟格式的总时间为08:00

（在具有ThreeTen Backport的Java 1.7.0_67上进行了测试。）

在其他答案（SimpleDateFormat，Date，DateFormat和Calendar中使用的日期时间类都已经过时且设计不良。可能更糟的是，一个答案是在没有任何库类帮助的情况下“手动”解析和计算。这很复杂且容易出错，从不建议这样做。相反，我使用的是java.time，这是现代的Java日期和时间API。与之合作真是太好了。

问题：我可以在Android上使用java.time吗？

是的，java.time在较新和较旧的Android设备上均可正常运行。它只需要至少 Java 6 。

在Java 8和更高版本以及更新的Android设备（API级别26以上）中，内置了现代API。
在Java 6和7中，获得了ThreeTen反向端口，这是现代类的反向端口（JSR 310的ThreeTen；请参见底部的链接）。
在（较旧的）Android上，使用Android版本的ThreeTen Backport。叫做ThreeTenABP。并确保您从org.threeten.bp导入日期和时间类别，并带有以下子包：org.threeten.bp.Duration，org.threeten.bp.LocalTime和org.threeten.bp.format.DateTimeFormatter。

链接

Oracle tutorial: Date Time解释了如何使用java.time。
Java Specification Request (JSR) 310，其中首先描述了java.time。
ThreeTen Backport project，是java.time向Java 6和7（JSR-310的ThreeTen）的反向端口。
ThreeTenABP，ThreeTen Backport的Android版
Question: How to use ThreeTenABP in Android Project，其中有非常详尽的解释。

Answer 5

请试试这个......

SimpleDateFormat simpleDateFormat = new SimpleDateFormat("HH:mm");

    try {
        date1 = simpleDateFormat.parse("08:00 AM");
    } catch (ParseException e) {
        e.printStackTrace();
    }

    try {
        date2 = simpleDateFormat.parse("04:00 PM");
    } catch (ParseException e) {
        e.printStackTrace();
    }

    long difference = date2.getTime() - date1.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);
    hours = (hours < 0 ? -hours : hours);
    Log.i("======= Hours", " :: " + hours);

Answer 6

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

Answer 7

String mStrDifferenceTime =compareTwoTimeAMPM("11:06 PM","05:07 AM");
Log.e("App---Time ", mStrDifferenceTime+" Minutes");

public static String getCurrentDateUsingCalendar() {
    Date mDate = new Date();  // to get the date
    @SuppressLint("SimpleDateFormat") SimpleDateFormat mSimpleDateFormat = new SimpleDateFormat("dd-MM-yyyy"); // getting date in this format
    return mSimpleDateFormat.format(mDate.getTime());
}

public static String getNextDateUsingCalendar() {
    Calendar mCalendar = Calendar.getInstance();
    mCalendar.add(Calendar.DAY_OF_YEAR, 1);
    Date mStrTomorrow = mCalendar.getTime();
    @SuppressLint("SimpleDateFormat") DateFormat mDateFormat = new SimpleDateFormat("dd-MM-yyyy");
    return mDateFormat.format(mStrTomorrow);

}

public static String compareTwoTimeAMPM(String mStrStartTime, String mStrEndTime) {
    String mStrCompareStartTime[] = mStrStartTime.split(" ");
    String mStrCompareEndTime[] = mStrEndTime.split(" ");
    int mIStartTime = Integer.parseInt(mStrCompareStartTime[0].replace(":", ""));
    int mIEndTime = Integer.parseInt(mStrCompareEndTime[0].replace(":", ""));
    String mStrToday = "";
    String mStrTomorrow = "";
    if (mIStartTime < mIEndTime && mStrCompareStartTime[1].equals("PM") && mStrCompareEndTime[1].equals("PM")) {
        mStrToday = getCurrentDateUsingCalendar();
        mStrTomorrow = getCurrentDateUsingCalendar();
    } else if (mIStartTime < mIEndTime && mStrCompareStartTime[1].equals("AM") && mStrCompareEndTime[1].equals("AM")) {
        mStrToday = getCurrentDateUsingCalendar();
        mStrTomorrow = getCurrentDateUsingCalendar();
    } else if (mIStartTime > mIEndTime && mStrCompareStartTime[1].equals("PM") && mStrCompareEndTime[1].equals("PM")) {
        String mStrTime12[] = mStrCompareStartTime[0].split(":");
        if (mStrTime12[0].equals("12")) {
            mStrToday = getNextDateUsingCalendar();
            mStrTomorrow = getNextDateUsingCalendar();
        } else {
            mStrToday = getCurrentDateUsingCalendar();
            mStrTomorrow = getNextDateUsingCalendar();
        }
    } else if (mIStartTime > mIEndTime && mStrCompareStartTime[1].equals("AM") && mStrCompareEndTime[1].equals("AM")) {
        String mStrTime12[] = mStrCompareStartTime[0].split(":");
        if (mStrTime12[0].equals("12")) {
            mStrToday = getNextDateUsingCalendar();
            mStrTomorrow = getNextDateUsingCalendar();
        } else {
            mStrToday = getCurrentDateUsingCalendar();
            mStrTomorrow = getNextDateUsingCalendar();
        }
    } else if (mStrCompareStartTime[1].equals("PM") && mStrCompareEndTime[1].equals("AM")) {
        mStrToday = getCurrentDateUsingCalendar();
        mStrTomorrow = getNextDateUsingCalendar();
    } else if (mStrCompareStartTime[1].equals("AM") && mStrCompareEndTime[1].equals("PM")) {
        mStrToday = getCurrentDateUsingCalendar();
        mStrTomorrow = getCurrentDateUsingCalendar();
    }
    @SuppressLint("SimpleDateFormat") SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd-MM-yyyy hh:mm aa");
    String mStrDifference = "";
    try {
        Date date1 = simpleDateFormat.parse(mStrToday + " " + mStrStartTime);
        Date date2 = simpleDateFormat.parse(mStrTomorrow + " " + mStrEndTime);
        mStrDifference = differenceDatesAndTime(date1, date2);
    } catch (ParseException e) {
        e.printStackTrace();
    }

    return mStrDifference;

}


public static String differenceDatesAndTime(Date mDateStart, Date mDateEnd) {

    long different = mDateEnd.getTime() - mDateStart.getTime();
    long secondsInMilli = 1000;
    long minutesInMilli = secondsInMilli * 60;
    long hoursInMilli = minutesInMilli * 60;
    long daysInMilli = hoursInMilli * 24;

    long elapsedDays = different / daysInMilli;
    different = different % daysInMilli;

    long elapsedHours = different / hoursInMilli;
    different = different % hoursInMilli;

    long elapsedMinutes = different / minutesInMilli;

    long minutes = elapsedHours * 60 + elapsedMinutes;
    long result = elapsedDays * 24 * 60 + minutes;
    if (0 > result) {
        result = result + 720;  //result is minus then add 12*60 minutes
    }

    return result + "";
}

我的输出是E / App ---时间：361分钟

在Android中计算两次之间的差异

7 个答案:

java.time和ThreeTenABP

问题：我可以在Android上使用java.time吗？

链接