Math.abs does not always give a positive result. Please consider other methods for positive random numbers.

Has Fix?

The problem

Math.abs returns a negative number when called with the largest negative number.


int veryNegative = Math.abs(Integer.MIN_VALUE);
long veryNegativeLong = Math.abs(Long.MIN_VALUE);

When trying to generate positive random numbers by using Math.abs around a random positive-or-negative number, there will be (very infrequent) occasions where the random number will be negative.

Instead, one should use random number generation functions that are guaranteed to generate positive numbers:

Random r = new Random();
int positiveNumber = r.nextInt(Integer.MAX_VALUE);

or map negative numbers onto the non-negative range:

long lng = r.nextLong();
lng = (lng == Long.MIN_VALUE) ? 0 : Math.abs(lng);


Suppress false positives by adding the suppression annotation @SuppressWarnings("MathAbsoluteRandom") to the enclosing element.