double型强转int型--向下取整；+0.5实现四舍五入

public class test2 {public static void main(String[] args) {// TODO Auto-generated method stubdouble a = 100.1;double b = 100.5;float c = 100.1f;float d = 100.5f;System.out.println((int)a);System.out.println((int)b);System.out.println(get(a));System.out.println(get(b));System.out.println(get(c));System.out.println(get(d));}private static int get(double n){return (int) (n+0.5);}}