package com.test;
  
import java.util.Random;
  
public class GenerateRandomNumber {
  
    public static void main(String[] args) {
  
        System.out.println("生成的10为随机数为：" + getCharAndNumr(10));
    }
  
    /**
     * java生成随机数字和字母组合
     * @param length[生成随机数的长度]
     * @return
     */
    public static String getCharAndNumr(int length) {
        String val = "";
        Random random = new Random();
        for (int i = 0; i < length; i++) {
            // 输出字母还是数字
            String charOrNum = random.nextInt(2) % 2 == 0 ? "char" : "num"; 
            // 字符串
            if ("char".equalsIgnoreCase(charOrNum)) {
                // 取得大写字母还是小写字母
                int choice = random.nextInt(2) % 2 == 0 ? 65 : 97; 
                val += (char) (choice + random.nextInt(26));
            } else if ("num".equalsIgnoreCase(charOrNum)) { // 数字
                val += String.valueOf(random.nextInt(10));
            }
        }
        return val;
    }
      
}