How to round a double to closest even number

Question

I want to round a double value to the next even integer number. e.g.:

• 489.5435 to 490
• 2.7657 to 2

I've tried Math.rint(), but it gives me 489 instead of 490.

Answer 1

Simply:

public static long roundEven(double d) {
    return Math.round(d / 2) * 2;
}

Gives:

System.out.println(roundEven(2.999));  // 2 
System.out.println(roundEven(3.001));  // 4