怎么用java 编调和平均数？

public class Harmonic {
public static void main(String args[]) {
int n = 5 ;
double harmonic = harmonic(n);

System.out.print(n+" 的和平均数是："+harmonic);
}

public static double harmonic(int num){
double harmonic = 0;
for(int i = 1;i<=num;i++){
harmonic = harmonic+(double)1/(double)i;
}
return (double)num/harmonic;
}
}
结果是：
5 的和平均数是：2.18978102189781

/**
*
*/
public double harmean(List<Integer> list){
int n =list.size();
double sum=0.0;
for(int i=0;i<list.size();i++){
sum+=1/list.get(i);
}
if(sum>0){
return n/sum;
}else{
return 0;
}
}