Safely casting long to int in Java
I think I'd do it as simply as:
public static int safeLongToInt(long l) {
if (l < Integer.MIN_VALUE || l > Integer.MAX_VALUE) {
throw new IllegalArgumentException
(l + " cannot be cast to int without changing its value.");
}
return (int) l;
}
I think that expresses the intent more clearly than the repeated casting... but it's somewhat subjective.
Note of potential interest - in C# it would just be:
return checked ((int) l);
A new method has been added with Java 8 to do just that.
import static java.lang.Math.toIntExact;
long foo = 10L;
int bar = toIntExact(foo);
Will throw an ArithmeticException
in case of overflow.
See: Math.toIntExact(long)
Several other overflow safe methods have been added to Java 8. They end with exact.
Examples:
Math.incrementExact(long)
Math.subtractExact(long, long)
Math.decrementExact(long)
Math.negateExact(long),
Math.subtractExact(int, int)