Hi,
This is my first time using java passions...so something is wrong please
teach me...
public class treemap {
public static void main(String[] args) {
Map m = new HashMap();
m.put(4, "four");
m.put(1, "one");
m.put(3, "three");
m.put(2, "two");
printMap(m);
Map tm = new TreeMap();
tm.putAll(m);
printMap(tm);
}
private static void printMap(Map m) {
System.err.println("priniting map:"+m);
for (Iterator it = m.values().iterator(); it.hasNext();) {
System.err.println(it.next());
}
System.err.println("----------------");
}
}
output:
priniting map:{1=one, 2=two, 3=three, 4=four}
one
two
three
four
----------------
priniting map:{1=one, 2=two, 3=three, 4=four}
one
two
three
four
----------------
so what is ur problem....
tm.putAll(m); //what is 'm' object...
On Tue, Apr 21, 2009 at 2:34 AM, Bakoly Takumah <[email protected]> wrote:
> Hi everyone,
> In the lab 1016, 3.1 build and run a simple application that uses HashMap,
> and part 4 of this segment advise us to do our own exercise : please do the
> following .... display them in both unsorted and sorted order.
> I did the unsorted order and it goes well, but I have a problem with the
> unsorted order, I got an execption : java.lang.ClassCastException.
> I use putAll() method like that :
>
> Map tm = new TreeMap();
> tm.putAll(m);
> And then display tm.
>
> I have looked at the JavaDoc about this exception for putAll but I don't
> really understand what it means :
> ClassCastException - if the class of a key or value in the specified map
> prevents it from being stored in this map
> Please, help.
> Thanks in advance.
> Bako
>
>
>
> >
>
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