取数字和字母的随机数

package com.slei.order;


public class Untitled1 {

    public String getRandomString(int random, int len) {
        java.util.Random rd = new java.util.Random(random);
        StringBuffer sb = new StringBuffer();
        int rdGet; // 取得随机数

        char ch;

        for (int i = 0; i < len; i++) {
            //rdGet = Math.abs(rd.nextInt()) % 10 + 48; // 产生48到57的随机数(0-9的键位值)
            rdGet = Math.abs(rd.nextInt()) % 26 + 97; //产生97到122的随机数(a-z的键位值)
            ch = (char) rdGet;
            sb.append(ch);
        }

        return sb.toString();
    }

    public static void main(String[] args) {
        Untitled1 dao = new Untitled1();
        System.out.println(dao.getRandomString(2, 16));
        System.out.println(dao.getRandomString(3, 16));
    }
}