Decimal Format

import java.text.DecimalFormat;

public class Demo {
    public static void main(String[] args) {

        DecimalFormat df = new DecimalFormat("#.###");

        double numberOne = 2.3265683;
        double numberTwo = 12.000000;

        System.out.printf("%s%n", df.format(numberOne)); // 2.327
        System.out.printf("%s", df.format(numberTwo)); // 12
    }
}