I am writing in a CSV and my calendar is doubling values ... I couldn't figure out the problem.
PS: Amount is like 1.000.000 or 10.000.000.
public static void CSV(String path, int amount) {
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Calendar c = Calendar.getInstance();
c.set(1980, 01, 01);
for (; set.size() < amount;) {
c.set(Calendar.MINUTE, c.get(Calendar.MINUTE) + 2);
set.add(c.getTime());
}
Iterator<Date> it = set.iterator();
for (int i = 0; i < amount; i++) {
csvWriter.append(dateFormat.format(it.next()));
}
...
}
Well, the error was the Hour in am/pm (1-12).
Thanks to #Teemu.
I assume you mean "doubling values" by that the same time occurs twice. Reason for that is your date formatter:
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
You are formatting hours as 'hh'. Meaning that it is formatting date as Hour in am/pm (1-12) . So two time values are actually unique, one is AM and another is PM. You are not providing the AM / PM markings into SimpleDateFormat and that's why both time values looks the same.
If you want to distinquish the AM / PM markings change the format to this:
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss aaa");
Or another way is to format hours in 0-23 format
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Not sure if my assumption is correct but I hope this helps.
Related
When I convert the String "07/02/2014" (mm/dd/yyy) to a java.util.Date using SimpleDateFormatter I get a result of Sun Dec 29 00:00:00 CAT 2013.
Here is the code I am running:
DateFormat formatter;
formatter = new SimpleDateFormat("MM/DD/YYYY");
Date exactDate = formatter.parse("07/02/2014");
Why is this happening ?
It must be:
DateFormat formatter;
formatter = new SimpleDateFormat("MM/dd/yyyy");
Date exactDate = formatter.parse("07/02/2014");
The documentation explains why.
y Year
Y Week year
D Day in year
d Day in month
M Month in year
m Minute in hour
Try this one,
DateFormat formatter = new SimpleDateFormat("MM/dd/yyyy");
Date exactDate = formatter.parse("07/02/2014");
When you print the Date object you will get that output. Try formatting Date into String for desired format and output.
Try following code:
DateFormat formatter = new SimpleDateFormat("MM/dd/yyyy");
Date exactDate = formatter.parse("07/02/2014");
String date=new SimpleDateFormat("MM/dd/yyyy").format(exactDate);
Hope this helps.
I have an issue where I would like to get the start of the day, however it seems to be setting it to 12:00 via automatic.
SimpleDateFormat dfFull = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
String todayDate = dfFull.parse("2014-06-06 00:00:00");
today = dfFull.format(todayDate);
System.out.println(today);
Why is this spitting out:
2014-06-06 12:00:00
The 12:00:00 is the issue
That is because hh represents the hour in 12 hour format. You need to use HH instead.
SimpleDateFormat dfFull = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Have a look at the docs for more info.
Also, on a side note, there is a typo in your code.
SimpleDateFormat dfFull = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date todayDate = dfFull.parse("2014-06-06 00:00:00"); // todayDate must be of type Date and not String
String today = dfFull.format(todayDate); // today should be of type String
System.out.println(today);
You should use HH for hours in this case.
SimpleDateFormat dfFull = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String todayDate = dfFull.parse("2014-06-06 00:00:00");
today = dfFull.format(todayDate);
System.out.println(today);
Now you will get the out put as
2014-06-06 00:00:00
And again if you use hh that mean you are using 12 hour format while HH means 24 hour format
So
I have to parse "17-Jun" format date using Java.But the problem is when I try to parse "dd-MM" format using SimpleDateFormat it is returning as "Wed Jun 17 00:00:00 IST 1970".Is it possible to get current(2014) year instead of 1970.
My result:
17/JUNE/1970
Expected result:
17/JUNE/2014
Have a look at this..
Calendar c = Calendar.getInstance();
c.set(Calendar.DATE, 17);
c.set(Calendar.MONTH, 5);
c.set(Calendar.YEAR, c.get(Calendar.YEAR));
Date date=new Date(c.getTimeInMillis());
SimpleDateFormat simpleDateformatter = new SimpleDateFormat("dd/mmm/yyyy");
String convertedDate = simpleDateformatter .format(date);
To get year you can just use
Calendar cal = Calendar.getInstance();
cal.get(Calendar.YEAR) will fetch you current year
Hope it helped... :)
Try this
Calendar c = Calendar.getInstance();
c.set(Calendar.DATE, 17);
c.set(Calendar.MONTH, 5);
c.set(Calendar.YEAR, c.get(Calendar.YEAR));
Date d=new Date(c.getTimeInMillis());
SimpleDateFormat formatter = new SimpleDateFormat("dd- mmm");
String conDate = formatter.format(d);
Do like this
Date date = new SimpleDateFormat("dd-MMM-yyyy").parse("17-Jun-"+ Calendar.getInstance().get(Calendar.YEAR));
You'll have to write a utility method, there isn't anything in SimpleDateFormat that will interpret a non-existant year as the current year. Something like this:
public static Date parseDate(String dateString) throws ParseException {
//determine current year
Calendar today = Calendar.getInstance();
int currentYear = today.get(Calendar.YEAR);
//parse input
SimpleDateFormat format = new SimpleDateFormat("dd-MMM");
Date parsed = format.parse(dateString);
// set current year on parsed value
Calendar cal = Calendar.getInstance();
cal.setTime(parsed);
cal.set(Calendar.YEAR, currentYear);
return cal.getTime();
}
Try this:
SimpleDateFormat dfDate = new SimpleDateFormat("dd-MM-yyyy");
java.util.Date d = null;
try {
d = dfDate.parse("17-Jun-"+ Calendar.getInstance().get(Calendar.YEAR));
} catch (java.text.ParseException e) {
e.printStackTrace();
}
System.out.println(""+d );
your problem will be solved.
java.time
In Java 8 you can do something like:
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("d-MMM");
MonthDay md = MonthDay.parse("17-Jun", dtf);
LocalDate d = LocalDate.now().with(md);
System.out.println(d.getDayOfMonth());
System.out.println(d.getMonthValue());
System.out.println(d.getYear());
I guess the simplest way is to do this:
DateFormat dateFormat = new SimpleDateFormat("yyyy/MMM/dd");
Date date = new Date();
System.out.println("Time is: " + dateFormat.format(date) );
This gives you exactly what you want. also see
http://docs.oracle.com/javase/tutorial/i18n/format/simpleDateFormat.html
Little late, but if you really don't want to use Calendar at all - as I gather from your comments to the correct answers above - (not recommended with the usage of deprecated methods, but still):
SimpleDateFormat format = new SimpleDateFormat("dd-MMM");
Date date = format.parse("17-JUN");
date.setYear(new Date().getYear());
System.out.println(date);
Output:
Tue Jun 17 00:00:00 IST 2014
All answers given here are more or less correct, but I notice that one detail aspect is still overlooked, namely if the combination of day and months fits to current year (february 29 problem). So I would suggest a strict parsing like following:
String ddMMM = "17-Jun";
SimpleDateFormat sdf = new SimpleDateFormat("dd-MMM-yyyy");
sdf.setLenient(false); // in order to check for "29-Feb"
TimeZone tz = TimeZone.getDefault(); // or change to your specific time zone
Date date =
sdf.parse(ddMMM + "-" + new GregorianCalendar(tz).get(Calendar.YEAR));
Try,
String s2 = "Wed Jun 17 00:00:00 1970";
SimpleDateFormat sdf1 = new SimpleDateFormat("E MMM dd hh:mm:ss yyyy");
SimpleDateFormat sdf2 = new SimpleDateFormat("dd/MMM/yyyy");
try {
Date d1 = sdf1.parse(s2);
System.out.println(d1);
String s3 = sdf2.format(d1);
System.out.println("Before Changing :: "+s3);
Calendar cal = Calendar.getInstance();
cal.setTime(d1);
cal.add(Calendar.YEAR, 2014-1970);
d1 = cal.getTime();
String s4 = sdf2.format(d1);
System.out.println("After Changing :: "+s4);
} catch (ParseException e) {
e.printStackTrace();
}
Output
Before Changing :: 17/Jun/1970
After Changing :: 17/Jun/2014
I have a question, how can I convert a string like 20130706123020 to a date object.
So I what to convert the string 20130706123020 to a date object looking like:
2013-07-06 12:30:20
Attempted code:
String date = "20130706234310";
Date date1 = new SimpleDateFormat("yyyy-m-d H:m:s").parse(date);
System.out.println(date1);
Any suggestions will be appreciated.
Thank you!
You have to first parse the String using the parse method from SimpleDateFormat.
Then pass the Date object returned by the parse method to another SimpleDateFormat and then using the format method get the date in the format you want.
String s = "201307061230202";
SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmssSS"); // format in which you get the String
SimpleDateFormat sdf1 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); // format in which you want the date to be in
System.out.println(sdf1.format(sdf.parse(s)));
The significance of HH, hh, KK and kk in the hour field is different. I have used HH you can use the one according to your requirement.
H Hour in day (0-23)
k Hour in day (1-24)
K Hour in am/pm (0-11)
h Hour in am/pm (1-12)
Use SimpleDateFormat
SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddhhmmss");
Date date = sdf.parse("20130706123020");
SimpleDateFormat sdf2 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println(sdf2.format(date));
use this :
long int my_date = 20130706123020L
and after that :
String date_Text = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date(my_date));
I went to display the current date and the six (6) last dates
example :
02/11/2012
01/11/2012
31/10/2012
30/10/2012
29/10/2012
28/10/2012
to get the current day in JAVA I used :
Date date = Calendar.getInstance().getTime();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
System.out.println("current day : "+sdf.format(date));
but how do I decrement the days ?
You can use the Calendar#add method to substract a day, like:
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
Calendar cal = Calendar.getInstance();
Date date=cal.getTime();
System.out.println(sdf.format(date)); //remove line to display only the last 5 days
for (int i=0;i<5;i++){
cal.add(Calendar.DAY_OF_MONTH,-1);
date=cal.getTime();
System.out.println(sdf.format(date));
}
Like Jon Skeet (soon Mr. 500k :) ) suggested, I too find the Joda Time API more cleaner and appropriate, even for such simple tasks:
DateTime dt = new DateTime();
for (int i = 0; i < 6; i++) {
System.out.println(dt.toString("yyyy/MM/dd"));
dt = dt.minusDays(1);
}
Calendar c = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
System.out.println("current day : "+sdf.format(c.getTime()));
// decrement 1 day
c.add(Calendar.DAY_OF_MONTH, -1);
// getTime() returns a java.util.Date
System.out.println("the day before : "+sdf.format(c.getTime()));
// getTimeInMillis() returns a long, which can be used to construct a java.sql.Date
System.out.println("the day before : "+sdf.format(new java.sql.Date(c.getTimeInMillis()));
And so on...