Java随机产生10位长度的字符串

import java.util.Random;
 
public class TestRandom {
    public static Random r = new Random();
         
    public static String getRandom(){
        long num = Math.abs(r.nextLong() % 10000000000L);
        String s = String.valueOf(num);
        for(int i = 0; i < 10-s.length(); i++){
            s = "0" + s;
        }
         
        return s;
    }
     
    public static void main(String[] args) {
        for(int i = 0; i < 10; i++){
            System.out.println(getRandom());
        }
    }
}