java - Want to divide long (huge file size in TBs) by some number (huge int) and safely get an int

Question

I want to divide long (huge file size in TBs) by some number (huge int) and safely get an int. But with the type conversion properties both int becomes long and the result is long. I'm sure my quotient will be an int, is casting ok or please direct me to a better solution.

Answer 1

Well if casting is okay, then just cast!

long size = ...;
int divisor = ...;
int result = (int) (size / divisor);

Of course you should only do this if you're sure that the result will genuinely be in the range of an int - you could always check that of course:

long size = ...;
int divisor = ...;
long fullResult = size / divisor;
if (fullResult < Integer.MIN_VALUE || fullResult > Integer.MAX_VALUE) {
    // Whatever, e.g. throw an exception
}
int result = (int) fullResult;

Answer 2

Use an explicit downcast:

long l_quot=l_size/(long)i_divisor;
int i_qout=(int)l_quot;