asked on

Java date object from a long

When i do the following

Date date = new Date(inputStream.readLong());

i get

[Mon Aug 04 10:20:00 BST 4093952]

it looks like the 'century' bit at the is not correct

Does java have an equivalent to c# - DateTime.FromFileTime(long val)

If not, how to i change my code to make work correctly.

Thanks

Ajay-Singh

Change it to:

File file = ...// Initialize the file.
Date date = new Date(file.lastModified());

Molko

ASKER

if its any help the value from

inputStream.readLong() is 129130498200000000

Molko

ASKER

I think the Date should be 03/14/2010 14:17:00

The hex i am reading in is 00 56 E1 02 81 C3 CA 01

which i guess is

char hexData[8] = {
0x00, 0x56, 0xE1, 0x02, 0x81, 0xC3, 0xCA, 0x01
};

Mick Barry

> inputStream.readLong() is 129130498200000000

> I think the Date should be 03/14/2010 14:17:00

what makes you think that?

that value certainly isn't, where is the value coming from?

ASKER CERTIFIED SOLUTION

Venabili

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Venabili

Just a confirmation link or two (googled after posting because wanted to verify the date on which the .NET starts counting):
http://social.msdn.microsoft.com/Forums/en-US/visualjsharpgeneral/thread/e0bbfaf0-e261-425e-b13f-b270fbc1de21
http://msdn.microsoft.com/en-us/library/system.datetime.fromfiletime.aspx

So I guess that my memory about it was correct after all. :)

Molko

ASKER

Objects - Thanks, I know the date should be 03/14/2010 14:17:00 as the binary file I reading in had a list of dates relating to files on my PC. The files on my PC have the datetime as 03/14/2010 14:17:00.

Venabili - Thanks, that looks like a great lead, i'll read up on that now. Thanks again

Cheers guys !

Venabili

:) Have fun - I think I had done it like this at least once (or it had been the opposite direction - cannot remember now) :)

Post back if you have issues and we will try to help.

Molko

ASKER

Hi

I think you were very much correct. I have done some research and the NanoSeconds/Milliseconds, 1601/1970 was exactly my problem.

       long dateMs = inputStream.readLong(); //129130498200000000
       System.out.println("Date in Nanos[" + dateMs + "]");

       // Microsoft FileTime/Date Epoch is January 1, 1601
       // Java Date Epoch is January 1, 1970, so take the number and subtract java Epoch:
       dateMs = dateMs - 0x19db1ded53e8000L;
       //convert UNITS from Nanoseconds(Microsoft) to Milliseconds (java)
       dateMs /= 10000L;
       System.out.println("Date in Ms[" + dateMs + "]");

       Date date = new Date(dateMs);
       SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss");
       String dateString = simpleDateFormat.format(date);

       System.out.println("ModifiedDate [" + dateString + "]");

And it give the correct result

Venabili

Yeah - why MS cannot play nicely and accept the Unix time is beyond me.

Do you need any more help here? :)