one question about the Date Class!

[Hiep Nguyen]

i new an instance of Data clase, and pass for it a long number. when i print it, it print : "January 1, 1970, 00:00:00 GMT". i want to print the date the the long number contain. but i don't know how to get it
can you help me?
thank you!

[Marilyn Monickam]

Hiep,
The Date constructor that takes a long

'Allocates a Date object and initializes it to represent the specified number of milliseconds since the standard base time known as "the epoch", namely January 1, 1970, 00:00:00 GMT.'
So if you construct a date object with this constructor and if you want to get the same long printed you should be using the method getTime() on the object created.
Hope this helps
Marilyn

[Jim Yingst]

Can you give us some code that demonstrates what you're doing? It sounds like the long value that you're using to set the Date, is 0. What happens if you try using a different value for the long?
Take a look at this code to see how it works:

    long num = System.currentTimeMillis();
    System.out.println("Current time as long: " + num);
    Date date = new Date(num);
    System.out.println("Current time as Date: " + date);
    for (long value = 1; value < 100000000000000L; value *= 10)
    {
      System.out.println("Value: " + value + "\tDate: " + new Date(value));
    }

[Hiep Nguyen]

this is the code that i test

public class Test {
    /**
    * @param args the command line arguments
    */
    public static void main (String args[]) {
        System.out.println(new java.util.Date(943921260).toLocaleString());
        System.out.println(new java.util.Date(943921260).toGMTString());
        System.out.println(new java.util.Date(943921260).toString());
    }
}

anh this is the result when i run the code
[result]
Jan 12, 1970 5:12:01 AM
11 Jan 1970 22:12:01 GMT
Mon Jan 12 05:12:01 GMT+07:00 1970
[/result]
thank you for your replies!

[Jim Yingst]

What version of JDK are you using? When you compiled, did you notice any warning messages? (Never ignore warning messages.)

[Marilyn Monickam]

Hiep,
So did you try adding this statement to get the long value?
System.out.println(new java.util.Date(943921260).getTime());
Marilyn

[Hiep Nguyen]

i'm using jdk1.3
yes, it has these warning

Note: C:\qos\testprint\Test.java uses or overrides a deprecated API.
Note: Recompile with -deprecation for details.
Finished Test.

so what is my mistake?
thank you so much !

[Jim Yingst]

Oops, false alarm - I saw that there were warnings, and without looking further I assumed that the deprecated methods were the source of your trouble. Turns out that's not really the case. You should still avoid deprecated methods though. If we follow the instructions:
Note: Recompile with -deprecation for details
That means compile like this:

javac -deprecation Test.java

(plus any other compiler flags you wish to use). This gives you additional information:

D:\Java\test\Test.java:10: warning: toLocaleString() in java.util.Date has been deprecated
        System.out.println(new java.util.Date(943921260).toLocaleString());
                           ^
D:\Java\test\Test.java:11: warning: toGMTString() in java.util.Date has been deprecated
        System.out.println(new java.util.Date(943921260).toGMTString());

Basically this tells us exactly which methods are considered incorrect to use. Typically you can look in the API for these methods, but in this case there's not a lot of information there. The short answer is, don't use these methods; they'll confuse us. Use toString(), or use a DateFormat object instead.
Anyway, that's probably just a distraction I think from your original question. You originally said:
i new an instance of Data clase, and pass for it a long number. when i print it, it print : "January 1, 1970, 00:00:00 GMT"
Now in your last code shown, that's no longer true - you are getting a different time, Mon Jan 12 05:12:01 GMT+07:00 1970. (Also expressed in several other formats; all equivalent.) Looks like a perfectly good result to me. So, does this mean that your original question has been answered to your satisfaction? Were you expecting some other result?

[Hiep Nguyen]

thank you!
but these are not the right result as you can see, if you pass any value it allways has results look like that. i also use DateFormat class. however, i have these same results.
this is my code

import java.util.Date;
import java.text.DateFormat;
import java.util.Locale;
public class Test {
public static void main (String args[]) {
Date date = new Date(943921260L);
DateFormat format = DateFormat.getDateInstance(DateFormat.SHORT,Locale.ENGLISH);

System.out.println(format.format(date));
}
}

and this is the result

1/12/70

the right result mus has year 1999
thank you one more !

[Jim Yingst]

but these are not the right result as you can see
No, actually I don't see what's wrong with these results.
When you pass in a long value of 943921260, that represents a date/time exactly 943921260 milliseconds after 12:00 A.M. GMT on Jan 1, 1970. That's 943921.260 seconds, or 15732 minutes, or 262 hourse, or 10.9 days. Which takes you to late Jan 11 using GMT, which is early Jan 12 in some time zones. That's what you're getting.
I guess the question is, where did the number 943921260 come from, and what sort of date were you expecting to get from it?