从控制输入n个数,计算n个数中偶数的平均数,java如何实现

public class TestNum {
public static void main(String[] args) {
Scanner sca = new Scanner(System.in);
int num = 0;
int sum = 0;
int n = 0;//计数器
System.out.println("请输入正整数,输入-1退出");
while(true){
num = sca.nextInt();
System.out.println(num/2);
if(num%2 == 0){
sum = sum + num;
n = n + 1;
}
if(num == -1){//-1表示结束
break;
}
}
System.out.println(sum);
System.out.println(n+"个偶数整数的平均值为："+sum/n);
}
}