Question

我想以AM / PM格式显示时间。示例：上午9:00 我也想进行加法减法运算。我的活动将从上午9:00开始。我想添加分钟来获得结果计划事件。除了制作自定义Time类之外，我怎么能这样做呢？

从上午9:00开始加入后加入45分钟开始时间上午9:45

Answer 1

从SimpleDateFormat开始，这将允许您解析和格式化时间值，例如......

SimpleDateFormat sdf = new SimpleDateFormat("hh:mm a");
try {
    // Get the start time..
    Date start = sdf.parse("09:00 AM");
    System.out.println(sdf.format(start));
} catch (ParseException ex) {
    ex.printStackTrace();
}

这样，您就可以使用Calendar来操纵日期值的各个字段......

Calendar cal = Calendar.getInstance();
cal.setTime(start);
cal.add(Calendar.MINUTE, 45);
Date end = cal.getTime();

并将它们放在一起......

SimpleDateFormat sdf = new SimpleDateFormat("hh:mm a");
try {
    Date start = sdf.parse("09:00 AM");
    Calendar cal = Calendar.getInstance();
    cal.setTime(start);
    cal.add(Calendar.MINUTE, 45);
    Date end = cal.getTime();

    System.out.println(sdf.format(start) + " to " + sdf.format(end));
} catch (ParseException ex) {
    ex.printStackTrace();
}

输出09:00 AM to 09:45 AM

<强>更新

或者您可以使用JodaTime ...

DateTimeFormatter dtf = new DateTimeFormatterBuilder().appendHourOfDay(2).appendLiteral(":").appendMinuteOfHour(2).appendLiteral(" ").appendHalfdayOfDayText().toFormatter();
LocalTime start = LocalTime.parse("09:00 am", dtf);
LocalTime end = start.plusMinutes(45);

System.out.println(start.toString("hh:mm a") + " to " + end.toString("hh:mm a"));

或者，如果您正在使用Java 8，那么新的日期/时间API ......

DateTimeFormatter dtf = new DateTimeFormatterBuilder().appendPattern("hh:mm a").toFormatter();
LocalTime start = LocalTime.of(9, 0);
LocalTime end = start.plusMinutes(45);

System.out.println(dtf.format(start) + " to " + dtf.format(end));

Answer 2

java.time

我想贡献现代的答案

Intent notificationIntent = new Intent(context, MainActivity.class);
PendingIntent contentIntent = PendingIntent.getActivity(context, 0, notificationIntent, 0);

NotificationCompat.Builder mBuilder =
    new NotificationCompat.Builder(context, "")
        .setSmallIcon(R.drawable.my_ic)
        .setContentTitle(title)
        .setContentText(msg)
        .setContentIntent(contentIntent);

输出为：

格式化时间：9:45 AM

在大多数其他答案中使用的// create a time of day of 09:00 LocalTime start = LocalTime.of(9, 0); // add 45 minutes start = start.plusMinutes(45); // Display in 12 hour clock with AM or PM DateTimeFormatter timeFormatter = DateTimeFormatter.ofLocalizedTime(FormatStyle.SHORT) .withLocale(Locale.US); String displayTime = start.format(timeFormatter); System.out.println("Formatted time: " + displayTime);，SimpleDateFormat和Date类不仅设计欠佳（尤其是第一个特别麻烦的地方），而且自Java以来它们也已经过时了四年前问这个问题时，现代Java日期和时间API .time已经不存在了。

为了向用户显示一段时间，我通常建议您从Calendar，DateTimeFormatter.ofLocalizedDate和.ofLocalizedTime获得的内置格式。如果您在某些情况下有内置格式无法满足的特殊格式需求，则也可以指定自己的格式，例如：

.ofLocalizedDateTime

（此特定示例没有意义，因为它给出的结果与上述相同，但是您可以将其用作起点并根据需要进行修改。）

链接： Oracle tutorial: Date Time解释了如何使用DateTimeFormatter timeFormatter = DateTimeFormatter.ofPattern("h:mm a", Locale.US);。

Answer 3

取自http://docs.oracle.com/javase/6/docs/api/java/text/SimpleDateFormat.html

 "h:mm a"   gives 12:08 PM

按时执行添加使用Calendar类

http://docs.oracle.com/javase/7/docs/api/java/util/Calendar.html#add(int,%20int)

 Calendar rightNow = Calendar.getInstance();  // or use your own Date
 rightNow.add (Calendar.MINUTE, 45);

 DateFormat dateFormat = new SimpleDateFormat("hh:mm a");

 System.out.println(dateFormat.format (rightNow)); --> showing as am / pm

Answer 4

找到许多例如here

的例子

import java.text.SimpleDateFormat;

import java.util.Date;

public class Main {

  public static void main(String[] args) {
    Date date = new Date();

    String strDateFormat = "HH:mm:ss a";
    SimpleDateFormat sdf = new SimpleDateFormat(strDateFormat);
    System.out.println(sdf.format(date));
  }
}
//10:20:12 AM

DateFormat dateFormat = new SimpleDateFormat("hh:mm a");

阅读this

Answer 5

使用Calendar

非常容易

    Calendar calendar =Calendar.getInstance();
    SimpleDateFormat sdf=new SimpleDateFormat("hh:mm a");
    sdf.format(calendar.getTime());
    System.out.println(sdf.format(calendar.getTime()));
    // i want to add 45mins now
    calendar.add(Calendar.MINUTE,45);
    System.out.println(sdf.format(calendar.getTime()));
    // i want to substract  30mins now
    calendar.add(Calendar.MINUTE,-30);
    System.out.println(sdf.format(calendar.getTime()));

Out put：

   10:49 AM
   11:34 AM
   11:04 AM

Answer 6

使用Simpledatetimeformat对象格式化时间和日历对象与日期以在日期对象上添加时间日期

Answer 7

使用日期模式获取它的最简单方法 - h：mm a，其中

h - Hour in am/pm (1-12)
m - Minute in hour
a - Am/pm marker
Code snippet :

DateFormat dateFormat = new SimpleDateFormat（“hh：mm a”）;

Answer 8

Calendar cl = new GregorianCalendar();
int a = cl.get(Calendar.AM_PM);
if(a == 1) {
                        lbltimePeriod.setText("PM");
                    }
                    else
                    {
                        lbltimePeriod.setText("AM");
                    }

这肯定会解决你的问题，它对我有效100％

Answer 9

   edit_event_time.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Calendar calendar =Calendar.getInstance();
            SimpleDateFormat sdf=new SimpleDateFormat("hh:mm a");
            String time = sdf.format(calendar.getTime());
            Log.e("time","time "+sdf.format(calendar.getTime()));
            String inputTime = time, inputHours, inputMinutes;

            inputHours = inputTime.substring(0, 2);
            inputMinutes = inputTime.substring(3, 5);

            TimePickerDialog mTimePicker = new TimePickerDialog(getActivity(), new TimePickerDialog.OnTimeSetListener() {
                @Override
                public void onTimeSet(TimePicker timePicker, int selectedHour, int selectedMinute) {

                    if (selectedHour == 0) {
                        selectedHour += 12;
                        timeFormat = "AM";
                    } else if (selectedHour == 12) {
                        timeFormat = "PM";
                    } else if (selectedHour > 12) {
                        selectedHour -= 12;
                        timeFormat = "PM";
                    } else {
                        timeFormat = "AM";
                    }

                    String selectedTime = selectedHour + ":" + selectedMinute + " " + timeFormat;

                    edit_event_time.setText(selectedTime);

                }
            }, Integer.parseInt(inputHours), Integer.parseInt(inputMinutes), false);//mention true for 24 hour's time format
            mTimePicker.setTitle("Select Time");
            mTimePicker.show();
        }
    });

Answer 10

有一个简单的代码来生成AM / PH的时间这里是我给你的代码请检查这个

import java.text.SimpleDateFormat; import java.util.Date;

public class AddAMPMToFormattedDate {

public static void main（String [] args）{

//create Date object
Date date = new Date();

 //formatting time to have AM/PM text using 'a' format
 String strDateFormat = "HH:mm:ss a";
 SimpleDateFormat sdf = new SimpleDateFormat(strDateFormat);

 System.out.println("Time with AM/PM field : " + sdf.format(date));

} }

如何以AM / PM格式显示时间

10 个答案:

java.time