Get a random time between two time - android

Time 1 : 10:30 06/05/2018
Time 2 : 19:45 06/05 2018
I want to pick a random time between these two time. The result may be (13:15 06/05/2018).
I look into Calendar but seem it does not support a method like range(time1, time2)
What is the solution for this case ? Thanks.

I would use something like this.
public static Calendar getRandomTime(Calendar begin, Calendar end){
Random rnd = new Random();
long min = begin.getTimeInMillis();
long max = end.getTimeInMillis();
long randomNum = min + rnd.nextLong()%(max - min + 1);
Calendar res = Calendar.getInstance();
res.setTimeInMillis(randomNum);
return res;
}
if you have API 21+, use ThreadLocalRandom
public static Calendar getRandomTime(Calendar begin, Calendar end){
long randomNum = ThreadLocalRandom.current().nextLong(begin.getTimeInMillis(), end.getTimeInMillis() + 1);
Calendar res = Calendar.getInstance();
res.setTimeInMillis(randomNum);
return res;
}

you should convert your times objects to long first as follows (I suppose that you have two Calendar objects already)
long time1InLong = time1.getTimeInMillis();
long time2InLong = time2.getTimeInMillis();
Then you can use following code to generate random number
Random r = new Random();
long randomTime = r.nextLong(time2InLong - time1InLong) + time1InLong;
Then you can convert this randomTime back to Calendar as follows
// Create a DateFormatter object for displaying date in specified format.
SimpleDateFormat formatter = new SimpleDateFormat("HH:mm dd/MM/yyyy");
// Create a calendar object that will convert the date and time value in milliseconds to date.
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(randomTime);

Related

Changing Textview Dynamicly after a certain period of Days

I'm quite new to Android and I want to change (I know how to set it dynamically but....)Textview Dynamically after a certain period of Days,but int the meantime keep the text posted unless changed by user or if a certain days have been reached by my program.
Well Basically I have the user to input a Date then i want my program to count days and as long as the user nor my program have intervene with the textview it will show the same text and backround color until the opposite is taken action.
here is my code:
String CurrentDate = new SimpleDateFormat("dd/MM/yyyy").format(new Date());
String FinalDate = TvDateOfService.getText().toString();
SimpleDateFormat dates = new SimpleDateFormat("dd/MM/yyyy");
Date dateinput;
Date datetwra;
//Setting dates
try {
dateinput = dates.parse(FinalDate);
datetwra = dates.parse(CurrentDate);
//Comparing dates
long difference = Math.abs(dateinput.getTime() - datetwra.getTime());
long differenceDates = difference / (24 * 60 * 60 * 1000);
//Convert long to String
String dayDifference = Long.toString(differenceDates);
//Calendar Instance to Add 89 Days for Service Period Between Dates!!
Calendar cal1 = Calendar.getInstance();
cal1.add(Calendar.DATE, 90);
Date ServicePeriod = cal1.getTime();
Calendar cal2 = Calendar.getInstance();
cal2.add(Calendar.DATE, 80);
Date DaysBeforeEnd = cal2.getTime();
do {
tvStatus.setBackground(getApplicationContext().getResources().getDrawable(R.drawable.textview_backround_green));
}while (dateinput.before(DaysBeforeEnd));
do {
tvStatus.setText("something");
tvStatus.setBackground(getApplicationContext().getResources().getDrawable(R.drawable.textview_backround_yellow));
}while (dateinput.after(DaysBeforeEnd));
do {
tvStatus.setText("something else");
tvStatus.setBackground(getApplicationContext().getResources().getDrawable(R.drawable.textview_backround_red));
}while (dateinput.after(ServicePeriod));
It looks like you're trying to use a for loop and wait a certain number of days - it would be most beneficial to the phone's battery if you used AlarmManager
https://developer.android.com/trai.../scheduling/alarms.html

Android, SimpleDateFormat not working

I'm trying to parse time only but the app code includes the date and the year.
here is my code:
simpleDateFormat2 = new SimpleDateFormat("HH:mm");
int h = Integer.parseInt(traffic.alarmClocks.get(0).get(ApplicationConstants.HOUR));
int m = Integer.parseInt(traffic.alarmClocks.get(0).get(ApplicationConstants.MINUTE));
String datex2 = h + ":" + m;
Date storedalarm = simpleDateFormat2.parse(datex2);
output of the datex2 is : 4:56
Output of StoredAlarm is this: http://imgur.com/a/UVpbh
The output of the datex2 is correct, but I need to make it into date because I am going to use it to compare times.
you just need to compare times you could very easily combine hours and minutes this way:
int time = hours * 60 + minutes;
then you could just compare 2 integers.
or if you really want a Date object, you could initialize it with year, month and date to 0, and just pass hours and minutes
Date storedalarm = new Date(0, 0, 0, h, m);
in order to show just hours and minutes from your Date object you can use the same SimpleDateFormat you instantiated before
String formattedDate = simpleDateFormat2.format(storedalarm);

How to get total number of months from a specific Date?

I am new to Android.I have a requirement, I have a field to enter the Date Of Birth of a person.On successful selection I wanna return the total number of months from the DOB to current date.For example, if I entered DOB as 19/10/2012 I wanna return 36(months).I searched for this, but didn't find anything suitable to my requirement.Here is my current code which return sucessful data,
private void showDate(int year, int month, int day) {
Calendar cal = Calendar.getInstance();
cal.setTimeInMillis(0);
cal.set(year, month, day);
Date date = cal.getTime();
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
if(System.currentTimeMillis() > date.getTime()) {
edtDate.setText(sdf.format(date));
LocalDate date1 = new LocalDate(date);
LocalDate date2 = new LocalDate(new java.util.Date());
PeriodType monthDay = PeriodType.yearMonthDayTime();
Period difference = new Period(date1, date2, monthDay);
int months = difference.getMonths();
months=months + 1;
System.out.println("16102015:Nunber of Months"+months);
}else{
Toast.makeText(mActivity,getResources().getString(R.string.date_validationmsg),Toast.LENGTH_LONG).show();
}
}
Calendar startCalendar = new GregorianCalendar();
startCalendar.setTime(startDate);
Calendar endCalendar = new GregorianCalendar();
endCalendar.setTime(endDate);
int diffYear = endCalendar.get(Calendar.YEAR) - startCalendar.get(Calendar.YEAR);
int diffMonth = diffYear * 12 + endCalendar.get(Calendar.MONTH) - startCalendar.get(Calendar.MONTH);
To start with, I'd suggest using LocalDate instead of DateTime for the computations. Ideally, don't use java.util.Date at all, and take your input as LocalDate to start with (e.g. by parsing text straight to that, or wherever your data comes from.) Set the day of month to 1 in both dates, and then take the difference in months:
private static int monthsBetweenDates(LocalDate start, LocalDate end) {
start = start.withDayOfMonth(1);
end = end.withDayOfMonth(1);
return Months.monthsBetween(start, end).getMonths();
}
UPDATE 1
see this link the OP is accepted the same answer because Months.monthsBetween() method is not working proper for him
UPDATE 2
LocalDate userEnteredDate = LocalDate.parse( new SimpleDateFormat("yyyy-MM-dd").format(date));
LocaleDate currentDate = LocalDate.parse( new SimpleDateFormat("yyyy-MM-dd").format(new Date()));
int months = monthsBetweenDates(userEnteredDate, currentDate)
Using Joda-time library here, I was able to get the desired result.
Try the below code it would give the desired the difference in months.
DateTime date1 = new DateTime().withDate(2012, 10, 19);
DateTime today = new DateTime().withDate(2015, 10, 19);
// calculate month difference
int diffMonths = Months.monthsBetween(date1.withDayOfMonth(1), today.withDayOfMonth(1)).getMonths();
Using JodaTime, it's really easy:
http://www.joda.org/joda-time/apidocs/
int nMonths = new Period(startTime, endTime).getMonths();
Use this code to calculate months between two dates
public static int monthsBetweenUsingJoda(Date d1, Date d2) {
return Months.monthsBetween(new LocalDate(d1.getTime()), new LocalDate(d2.getTime())).getMonths();
}

how to get correct date diffrence

i want to compare a date with the current date and do something if the difference is 2 months or 6 or a year .. but i have a problem how to get the correct difference for example if the current month is 02 2015 and the other month is 10 2014 i will get 8 in difference but the actual difference is 4 .. how to do it ?
Calendar c = Calendar.getInstance();
System.out.println("Current time => " + c.getTime());
SimpleDateFormat d = new SimpleDateFormat("dd");
SimpleDateFormat m = new SimpleDateFormat("MM");
SimpleDateFormat ye = new SimpleDateFormat("yyyy");
String day = d.format(c.getTime());
String month = m.format(c.getTime());
String year = ye.format(c.getTime());
int d1=Integer.parseInt(day);
int m1=Integer.parseInt(month);
int d2=25;
int m2=02;
int diff=d1-d2;
String s=String.valueOf(diff);
You are calculating your difference between two int, so it can't work.
You should calculate it between two dates or two long (in secondes or milliseconds)
long oneDay, today, delay;
oneDay = 1000*3600*24; //number of milliseconds in a day
today = Calendar.getInstance().getTimeInMillis();
delay = (TheDateYouWantToCompare - today)/oneDay;
if (delay >= 60*oneDay) { //more than 2 months
//your code
}else{
//your code
}
If TheDateYouWantToCompare and today are dates, it's almost the same :
delay = (TheDateYouWantToCompare.getTime() - today.getTime())/oneDay;
Edit :
Here it is how to get time in milliseconds.
String DateString = "31-12-2015";
SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
Date myDate = sdf.parse(DateString);
long timeInMilliseconds = myDate.getTime();
You could just use the difference in milliseconds between the 2 dates. Pre-compute the differences you need/want as constants and compare to the delta you have, for example:
static final long DAY = 1000 * 60 * 60 * 25;
static final long MONTH = DAY * 30;
...
int diff = d1 - d2;
if(diff > MONTH) {
//more than a month difference
}
If you need something more complex you should perhaps use a library such as Joda Time which will give a more comprehensive set of features to work with time.

How to get the day, year, hours, min Individually from date format "yyyy-MM-dd'T'HH:mm:ss.SSSZ"?

I am doing a programme that stores the present time and date in "yyyy-MM-dd'T'HH:mm:ss.SSSZ" this format. and I am storing it in database as a string. when i am collecting the data i need the individual values like day, year, min, seconds etc.. how can i do this?
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
String now = formatter.format(new Date());
Thank you,
Just use parse instead of format :
String dateFromDB = "";
SimpleDateFormat parser = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
Date yourDate = parser.parse(dateFromDB);
And then you can can read any field you want using java.util.Date & Calendar API :
Calendar calendar = Calendar.getInstance();
calendar.setTime(yourDate);
calendar.get(Calendar.DAY_OF_MONTH); //Day of the month :)
calendar.get(Calendar.SECOND); //number of seconds
//and so on
I hope it fits your needs
I'm suggesting that you store times in the DB as "timeInMillis". In my experience it simplifies code and it allows you to compare times values to eachother.
To store a time:
Calendar calendar = Calendar.getInstance(); // current time
long timeInMillis = calendar.getTimeInMillis();
mDb.saveTime (timeInMillis); // adjust this to work with your DB
To retrieve a time:
long timeInMillis = mDb.getTime();
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis (timeInMillis);
int milliSeconds = calendar.get(MILLISECOND);
//etc
There are these methods available to get the individual parts of a date
getDate()
getMinutes()
getHours()
getSeconds()
getMonth()
getTime()
getTimezoneOffset()
getYear()
Try using : int hour = Calendar.getInstance().get(Calendar.HOUR_OF_DAY);
Here,
Calendar.HOUR_OF_DAY gives you the 24-hour time.
Calendar.HOUR gives you the 12-hour time.

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