java求范围内的完数

编程找出m~n之间的所有完数，m和n为从键盘输入的两个整数。一个数如果恰好等于它的因子之和，这个数就称为 "完数 "。例如6=1＋2＋3。
package perfectnum;

import java.util.Scanner;

public class PerfectNum {
    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        int m = in.nextInt();
        int n = in.nextInt();
        System.out.print(m);
        System.out.print(" to"+n);
        System.out.println(" WanShu:");
        for(int i = m;i <= n;i++) {
            int sum = 0;//查找因数
            for(int j = 1;j < m;j++) {
                if(i % j == 0) {
                    sum = sum + j;//因数之和
                }
                if(sum == i) {//如果因数之和等于数本身则输出
                    System.out.print(i);
                    System.out.print(",");
                }
            }
        }
    }
}