Dates are not getting compared? - java

I am comparing dates in my android application, how ever for my equal dates, compareTo or equals method returns me that dates are not equal. I have debugged through and I can see both my objects have same values. But some how it is not working. Following is the way I am doing it:
public static boolean compareDates(long deliveryTime, Date date) throws ParseException {
Date deliveryDate = convertLongToDate(deliveryTime);
deliveryDate.setHours(0);
deliveryDate.setMinutes(0);
deliveryDate.setSeconds(0);
if (deliveryDate.equals(date))
{
return true;
}
return false;
}
My date object does not contain time, so I am setting deliverTime's time to 0(zero) as well, so that both objects can have same values. but it does not work. Any help is appreciated. Thanks!

I would create a Date object out of the deliveryTime, and then compare the hours, minutes and seconds. A code is below.
public static boolean compareDates(long deliveryTime, Date date) {
Date d = new Date(deliveryTime);
return(d.getHours() == date.getHours() && d.getMinutes() == date.getMinutes() && d.getSeconds() == date.getSeconds());
}

Would it not be easier to just compare deliveryTime to date.getTime() instead of converting deliveryTime to a Date?
Edit
Since you didn't mention you want to ignore milliseconds, you could do:
(deliveryTime / 1000) == (date.getTime() / 1000)
That should strip out the milliseconds. Alternatively,
Calendar c = Calendar.getInstance();
c.setTime(deliveryTime);
c.set(Calendar.MILLISECOND, 0);
//Clear out the other fields you don't care to compare
Date deliveryDate = c.getTime()

If you make date and deliverydate into date objects, then you can use
date.compareTo(deliveryDate);
This will return: 0 if the dates are the same, a value greater than 0 if date is more recent than deliveryDate, and a value less than 0 if date is before deliveryDate.
To get your dates into date format, you can use something like the following:
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Date date = sdf.parse(date);
Date deliveryDate = sdf.parse(deliveryTime);

Related

Java Date Comparison [duplicate]

This question already has answers here:
Comparing two java.util.Dates to see if they are in the same day
(14 answers)
How to know if a Date is within the same day of other date [duplicate]
(2 answers)
Closed 6 years ago.
According to Java API public boolean before(Date when)
true if and only if the instant of time represented by this Date
object is strictly earlier than the instant represented by when; false
otherwise.
Now I have to check if date input by user is greater than current date then only it will accept the input otherwise throw exception so i tried below
if(userInputDate.before(new Date())){
throw new Exception("Some Message");
}
But if both date are same then also it going to inside if statement .Do it mean it will calculate time and then check rather than comparing date? If yes how to resolve my issue ?
Can any one tell me how to add check for this?
The method before in the class Date is comparing the millisecond between the dates, so it's not comparing just the day, it is comparing the instant of time.
You could create a method to check if the dates are not in the same day and the first date is before the second one
public static boolean isBeforeDate(Date date1, Date date2) {
SimpleDateFormat fmt = new SimpleDateFormat("yyyyMMdd");
boolean areTheSameDay = fmt.format(date1).equals(fmt.format(date2));
return !areTheSameDay && date1.before(date2);
}
If you can use the new time api In Java8 instead of the old Date class, you can use the class LocalDate and the method compareTo:
boolean isBefore = myLocalDate.compareTo(myOtherLocalDate) < 0
All methods on java.util.Date that allow one to separate the time of day from the day of the year are deprecated. Therefore it is better to use java.util.Calendar. Additionally one should consider that there is typically one hour in each year that is in two days when summer time ends.
Here are two ways you can do it:
public static boolean isBeforeDay(Date date1, Date date2) {
// convert date1 to noon on the same day
Calendar day1 = Calendar.getInstance(TimeZone.getDefault());
day1.setTime(date1);
day1.set(Calendar.HOUR_OF_DAY, 12);
day1.set(Calendar.MINUTE, 0);
day1.set(Calendar.SECOND, 0);
day1.set(Calendar.MILLISECOND, 0);
// convert date2 to noon on the same day
Calendar day2 = Calendar.getInstance(TimeZone.getDefault());
day2.setTime(date2);
day2.set(Calendar.HOUR_OF_DAY, 12);
day2.set(Calendar.MINUTE, 0);
day2.set(Calendar.SECOND, 0);
day2.set(Calendar.MILLISECOND, 0);
return day1.before(day2);
}
public static boolean isBeforeDay(Date date1, Date date2) {
// get yyyymmdd value from date1
Calendar day1 = Calendar.getInstance(TimeZone.getDefault());
day1.setTime(date1);
int ymd1 = 10000*day1.get(Calendar.YEAR) + 100*day1.get(Calendar.MONTH) + day1.get(Calendar.DAY_OF_MONTH);
// get yyyymmdd value from date2
Calendar day2 = Calendar.getInstance(TimeZone.getDefault());
day2.setTime(date2);
int ymd2 = 10000*day2.get(Calendar.YEAR) + 100*day2.get(Calendar.MONTH) + day2.get(Calendar.DAY_OF_MONTH);
return ymd1 < ymd2;
}

get yesterday date from timestamp [duplicate]

This question already has answers here:
Get yesterday's date using Date [duplicate]
(8 answers)
Closed 8 years ago.
I've got an object with a field timestamp with type java.sql.Timestamp;.
And I need to get objects with yesterday date from a collection.
How to get them?
I mean I need something like this
for(int i = 0; i < items.size(); i++) {
(if the items.get(i).date == yesterday_date)
(get object)
}
You can get yesterday's Date by following approach Answered by Jiger Joshi.
And by using new Timestamp(java.util.Date) you can get yesterday's timestamp, you should use Timestamp#equals to equaling two different timestamp.
if (items.get(i).date.equals(getYesterdaytimestamp())){
...
}
And there are something which you must consider while implementing this. Calender#getTime which returns Date object and date object contains date with time, so in that case your equaling date or timestamp must be exactly equals with yesterday's date and time.
If requirement is, it needs to equal just yesterday no not where time is not considerable fact. In that case you need to equals two timestamp after discarding time part.
if (equalsWithYesterday(items.get(i).date)){
...
}
...
public boolean equalsWithYesterday(Timestamp st){
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd"); // Time part has discarded
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, -1);
Date yesterday = dateFormat.parse(dateFormat.format(cal.getTime())); // get yesterday's Date without time part
Date srcDate = new Date(st);
Date srcDateWithoutTime =dateFormat.parse(dateFormat.format(srcDate));
return yesterday.equals(srcDateWithoutTime ); // checks src date equals yesterday.
}
You can convert the timestamp object to date object like this:
Date date = new Date(items.get(i).getTime());
or you can simply use method Timestamp#compareTo(Date o)
items.get(i).compareTo(yesterday_date);
I hope you are not interested to compare the time?
Simply use Calendar class to extract the day, month, year etc. from the date and simply compare it.
Use Calendar#get() method to get the specific field from the date object.
How to subtract one day from the current date?
// get Calendar with current date
Calendar cal = Calendar.getInstance();
// get yesterday's date
cal.add(Calendar.DATE, -1);
// get components of yesterday's date
int month = cal.get(Calendar.MONTH) + 1; // 0 for January, 1 for Feb and so on
int day = cal.get(Calendar.DATE);
int year = cal.get(Calendar.YEAR);
// get yesterday's date in milliseconds
long lMillis = cal.getTime().getTime();

Comparing Just the Date (not time)

I need to compare 2 dates to a third date and ignore the time portion of all of them.
The code below generates a parse exception because the toString() method returns something like "Wed Feb 26 00:00:00 EST 2014".
Any suggestions on how I might fix this?
private boolean needToSendEmail(EmSelfCertEntity escd) throws ParseException {
boolean sendEmail = false;
DateFormat df = new SimpleDateFormat("MM/dd/yyyy");
Date justTheDate = df.parse(escd.getCurrentFCESDate().toString());
Calendar firstSent = Calendar.getInstance();
firstSent.setTime(justTheDate);
justTheDate = df.parse(new Date().toString());
Calendar firstFollowUp = Calendar.getInstance();
firstFollowUp.setTime(justTheDate);
firstFollowUp.add(Calendar.DATE, -daysToFirstFollowUpEmail);
Calendar secondFollowUp = Calendar.getInstance();
secondFollowUp.setTime(justTheDate);
secondFollowUp.add(Calendar.DATE, -daysToSecondFollowUpEmail);
if ((firstSent.before(firstFollowUp) && escd.countEmailsSent <= 1)
|| (firstSent.before(secondFollowUp) && escd.countEmailsSent <= 2)) {
sendEmail = true;
}
return sendEmail;
}
Thanks!
Why are you parsing the String when you already have the Date?
If you want to format your existing Date into the format you specified, use the format() method instead:
String justTheDate = df.format(new Date());
Then you can compare the Strings using the equals() method to check for matches.
Edit- By the way, if Java 8 is an option (it came out on Tuesday!), its new DateTime features will do exactly what you're looking for: http://docs.oracle.com/javase/tutorial/datetime/
The cause for your exception is that toString in escd.getCurrentFCESDate().toString()
delivers another format than "MM/dd/yyyy".
So make sure that either your format String in line SimpleDateFormat("MM/dd/yyyy") is correct.
Or check if you can get the year, month, and day directly from getCurrentFCESDate().
Just Use the calendar to create a date, where you take the year, months, day from the existing date but set the hours, minutes, seconds and millis to zero.
The result will be a Date object:
Something like
firstSent.set(Calendar.HOUR, 0);
firstSent.set(Calendar.MINUTE, 0);
firstSent.set(Calendar.SECOND, 0);
firstSent.set(Calendar.MILLISECOND, 0);
Then use before() and after()
The easiest approach would be to convert the dates to numbers in this format: yyyyMMdd.
And after that you can just compare the numbers.
But yes, please work with timezone adjustments before converting to numbers.
you can calculate the time in millis and substract the time with a simple / division.
This way you can compare 2 longs and check if one is bigger than another.
Take this example where we get to different dates for today (500 milliseconds from one to another) but... if you divide by 86400000 then... you get the same number.
Try this:
public static void main(String[] args) throws Exception {
Date d1= new Date();
Thread.sleep(500);
Date d2= new Date();
final int MILLISECONDS = 1000;
final int SECONDS = 60;
final int MINUTES = 60;
final int HOURS = 24;
final long MILLI_PER_DAY= MILLISECONDS*SECONDS*MINUTES*HOURS;
System.out.println(MILLI_PER_DAY);
System.out.println(d1.getTime());
System.out.println(d2.getTime());
System.out.println(d1.getTime()/MILLI_PER_DAY);
System.out.println(d2.getTime()/MILLI_PER_DAY);
}
You will see that the last 2 entries are the same:
1395338535623 --> time 1 in millis
1395338536123 --> time 2 in millis
16149 --> time 1 / 86400000
16149 --> time 2 / 86400000 --> THE SAME

How do I figure out whether the current time is in between two times? [duplicate]

This question already has answers here:
How can I determine if a date is between two dates in Java? [duplicate]
(11 answers)
Closed 9 years ago.
I'm trying to write a schedule program in Java and I need to figure out what time it is, and whether the current time is in between two set times. Figuring out the current time is pretty simple, but do you have any suggestions for figuring out whether it is between two times of day. For example, it is 9:33 AM on a Thursday. So I would need to figure out which scheduled section of the week that time corresponds to. How would I go about comparing the time to set periods during the week, for example an Array of sectioned times during a week such as {Monday from 9-10 AM, Tuesday from 3-4 PM, Thursday from 8-11 AM}, and seeing which section of time the current time falls between?
An efficient way to find which period any date lies within would be to have a class;
public class TimePeriod implements Comparable<TimePeriod>{
Date start;
Date end;
//Constructor, getters, setters
boolean isIn(Date date) {
return date.after(start) && date.before(end);
}
public int compareTo(TimePeriod other) {
return start.compareTo(other.start);
}
}
..and then create a sorted list of TimePeriod where you can perform a binary search.
edit:
This might make the binary search easier;
int check(Date date) {
if (isIn(date)) {
return 0;
} else if (start.after(date)) {
return -1;
} else if (end.before(date)) {
return 1;
} else {
throw new IllegalStateException("Time has gone badly wrong");
}
}
If you're using Date Class, you could do it like this
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy hh:mm");
Date before = sdf.parse("07/05/2012 08:00");
Date after = sdf.parse("07/05/2012 08:30");
Date toCheck = sdf.parse("07/05/2012 08:15");
//is toCheck between the two?
boolean isAvailable = (before.getTime() < toCheck.getTime()) && after.getTime() > toCheck.getTime();
EDITED
As suggested by Jonathan Drapeau you could also use compareTo.
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy hh:mm");
Date before = sdf.parse("07/05/2012 08:00");
Date after = sdf.parse("07/05/2012 08:30");
Date toCheck = sdf.parse("07/05/2012 08:15");
//is toCheck between the two?
if you want to include the "initial" and "final" date range
boolean isAvailable = before.compareTo(toCheck) >= 0 && after.compareTo(toCheck) <= 0
if you want to exclude the "initial" and "final" date range
boolean isAvailable = before.compareTo(toCheck) > 0 && after.compareTo(toCheck) < 0
You could use it too on Calendar class.
Anyway, i highly recommend you to use Calendar. It's a way precise class
you could check it like this:
Calendar cal1 = Calendar.getInstance(); // for example 12:00:00
Calendar cal2 = Calendar.getInstance(); // for exmaple 12:30:00
Calendar userTime = Calendar.getInstance(); // time to test: 12:15:00
if(user.after(cal1)&& user.before(cal2)){
//...
}
And to initialize and set times to Calendar, check this:
http://www.tutorialspoint.com/java/util/calendar_settime.htm
I would suggest using the Epoch time.
For a definition of Epoch time: http://en.wikipedia.org/wiki/Epoch_time
Basically, its a number of seconds after a specific date, i believe in 1989. If you translate the 3 times (the current time and the 2 times to compare to) in epoch time you can just use > < = etc.
For information on getting epoch time, Try here (has many languages): http://shafiqissani.wordpress.com/2010/09/30/how-to-get-the-current-epoch-time-unix-timestamp/
Unfortunately, my java is lacking or I'd give you some code :)
Edit:
Java epoch time code:
long epoch = System.currentTimeMillis()/1000;
Because my Java is bad and I don't have an interpreter where I am, I can only suggest using this site to help convert the other dates to epoch time: http://www.epochconverter.com/
There is before(Date) and after(Date) method in Date Class.
secondDate.before(firstDate)
If you use Calendar class, it has explicit before() and after() methods:
Calendar startDate = ...
Calendar endData = ...
isBetween = currentDate.after(startDate) && currentDate.before(endDate);

how to check : dateOne < dateTwo

I need help to check following conditions related to date and time...
Calendar cal = Calendar.getInstance();
SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
String CurrentDate= dateFormat.format(cal.getTime());
String ModifiedDate = dateTime taken from date n time picker widget ;
i have to check :
current ModifiedDate is not less than 5 minutes of current time
How to check this conditon in Android / Java..........?
Why are you formatting the date?
It's much easier to work with data in a "natural" representation rather than in a string representation. It's not clear whether your modified date has to be taken as a string, but if it does, the first thing you should do is parse it. You can then compare that with the current date and time using:
// Check if the value is later than "now"
if (date.getTime() > System.currentTimeMillis())
or
// Check if the value is later than "now + 5 minutes"
if (date.getTime() > System.currentTimeMillis() + TimeUnit.MINUTES.toMillis(5))
It's not really clear what you mean by "current ModifiedDate is not less than 5 minutes of current time" - whether you mean that it's not less than 5 minutes after, or not less than 5 minutes earlier, or something like that - but you should be able to change the code above to handle your requirements.
If you do a lot of date/time manipulation, I'd strongly recommend the use of Joda Time, which is a much better date/time API than java.util.Date/Calendar.
To check whether the given time is before/after the current time ,
There is a Calendar instance in Android...to compare date time values.
Calendar current_time = Calendar.getInstance ();
current_time.add(Calendar.DAY_OF_YEAR, 0);
current_time.set(Calendar.HOUR_OF_DAY, hrs);
current_time.set(Calendar.MINUTE, mins );
current_time.set(Calendar.SECOND, 0);
Calendar given_time = Calendar.getInstance ();
given_time.add(Calendar.DAY_OF_YEAR, 0);
given_time.set(Calendar.HOUR_OF_DAY, hrs);
given_time.set(Calendar.MINUTE, mins );
given_time.set(Calendar.SECOND, 0);
current_time.getTime();
given_time.getTime();
boolean v = current_calendar.after(given_calendar);
// it will return true if current time is after given time
if(v){
return true;
}
public static boolean getTimeDiff(Date dateOne, Date dateTwo) {
long timeDiff = Math.abs(dateOne.getTime() - dateTwo.getTime());
int day = (int) TimeUnit.MILLISECONDS.toHours(timeDiff);
int min= (int) ( TimeUnit.MILLISECONDS.toMinutes(timeDiff) - TimeUnit.HOURS.toMinutes(TimeUnit.MILLISECONDS.toHours(timeDiff)));
if(day>1)
{
return false;
}
else if(min>5)
{
return false;
}
else
{
return true;
}
}
usage:
System.out.println(getTimeDiff(new Date("01/13/2012 12:05:00"),new Date("01/12/2012 13:00:00")));

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