CODEWITHSUNDEEP
javadatetimecalendar
denBelg
denBelg

Reputation: 343

Increment calendar with day

I have a strange problem when i increment days in Calendar. I want to loop over every day of a year. This is my code

Date d = null;
SimpleDateFormat textFormat = new SimpleDateFormat("dd-MM-yyyy");
String paramDateAsString = "10-1-2012";
d = textFormat.parse(paramDateAsString);
Calendar cal = Calendar.getInstance(); 
cal.setTime(d);

for(int i = 0; i < 365; i++) {
   cal.add(Calendar.DAY_OF_YEAR, 1);
   System.out.println(cal.get(Calendar.YEAR)+"-"+cal.get(Calendar.MONTH)+1+"-         "+cal.get(Calendar.DAY_OF_MONTH)+" 00:00:00'");
}

I get this output:

...
2012-01-29 00:00:00'
2012-01-30 00:00:00'
2012-01-31 00:00:00'
2012-11-1 00:00:00'
2012-11-2 00:00:00'
...

Upvotes: 0

Views: 134

Answers (1)

Jon Skeet
Jon Skeet

Reputation: 1500504

This is the problem:

"-"+cal.get(Calendar.MONTH)+1

That's actually performing string concatenation - it's effectively

("-" + cal.get(Calendar.MONTH)) + 1

So when cal.get(Calendar.MONTH) returns 1, that's effectively:

("-" + 1) + 1 // which is...
"-1" + 1 // which is...
"-11"

You could just bracket the addition:

"-" + (cal.get(Calendar.MONTH) + 1)

... but it would be better to use SimpleDateFormat to perform the formatting instead of doing it manually.

Upvotes: 2

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