to compare the memory usage between the use of the static array and java.util.ArrayList in a sorting operation -

runtime rt = runtime.getruntime();   long  totalm = rt.totalmemory();   long  currentm;    int  []n = new int[10000];   system.out.print("10000 ints used: ");   system.out.println(totalm - rt.freememory()); 

its not working. cannot use long calculation?

thanks in advance, please give me suggestions

answering implicit question in title: difference in "memory usage between use of static array , java.util.arraylist in sorting operation".

in java 8: none. because sort delegated arraylist class, sorts backing array directly using arrays.sort().

in java 7 , below, list converted array, array sorted, , result put list. so, memory doubled array, plus whatever memory need sorting operation itself, depends on version of java.
happens linkedlist in java 8.