java.lang.IllegalArgumentException: Bad class: class java.util.GregorianCalendar

Question

I received this exception while using GregorianCalendar

java.lang.IllegalArgumentException: Bad class: class java.util.GregorianCalendar

Who know how to fix,

Please help me.

p/s : I used the following code :

Calendar someDate = GregorianCalendar.getInstance();
        someDate.add(Calendar.DAY_OF_YEAR, -7);
        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String formattedDate = dateFormat.format(someDate);

UPDATED I should be use this line to achieve the date time :

String formattedDate = dateFormat.format(someDate.getTime());

huh? don't understand your case clearly. But after do thing as u said. still can not fix issu — Huy Tower, Jun 04 '14 at 15:28

score 97 · Accepted Answer · answered Jun 04 '14 at 15:35

97

A Calendar can't be directly formatted, you need to get the Date from the Calendar, like this:

String formattedDate = dateFormat.format(someDate.getTime());

answered Jun 04 '14 at 15:35

wvdz

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Actually it's not so good to call a method like this, signature: `public final Date getTime()` (I expect get date method which will return time :) – xwild Mar 24 '16 at 08:51
@xwild What do you mean? – wvdz Mar 24 '16 at 15:10
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I mean calendar methods naming are not so good, getTime should return Time (i.e. 12:00), getDate shoud return Date (i.e. 2016-01-01), but now in java `getTime()` returns a `Date` instance. – xwild Mar 25 '16 at 05:24
`Calendar` is not a subclass of `Date`. Why does this compile on Android? – Peter Chaula Feb 20 '17 at 09:45
@peter: `Calendar.getTime()` retrieves the `Calendar` as a `Date`. – wvdz Feb 20 '17 at 12:23
@wvdz I mean `SimpleDateFormat::format(Calendar)`. It compiled on my Android app but then it threw a a runtime exception – Peter Chaula Feb 20 '17 at 13:30
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@peter. `SimpleDateFormat` extends `Format` which has `format(Object)`. – wvdz Feb 20 '17 at 13:39

score 2 · Answer 2 · edited May 23 '17 at 11:54

2

As one of the answers here: Using GregorianCalendar with SimpleDateFormat says "A SimpleDateFormat, as its name indicates, formats Dates."

So, try this:

String formattedDate = dateFormat.format(someDate.getDate());

edited May 23 '17 at 11:54

Community

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answered Jun 04 '14 at 15:35

Zoran

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`someDate.getTime()` will be return `Date`, not `someDate.getDate()` – Huy Tower Jul 02 '14 at 00:10

java.lang.IllegalArgumentException: Bad class: class java.util.GregorianCalendar

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