How To Take Runtime Value For Static Final Variable

How can i take run time value for static final variable...my lecturer said first time assignment is possible for declared final variable but in my case it shows compile time error..I'm placing my program below with error message

class Sample
{
static final String cname;
void print() {
System.out.println(cname);
}
public static void main(String args[])
{
cname=args[0];
Sample s=new Sample();
s.print();
}
}

Sample.java:11: cannot assign a value to final variable cname.
cname=args[0];