【0730拓展作业】随机生成6位的字符串验证码

需求：随机生成6位的字符串验证码，要求包含数字、大小写字母 

package com.random;

public class VerifyCode {
    public static String getCode(int length) {
        String code = "";
        for (int i = 0; i < length; i++) {
            boolean boo = (int) (Math.random() * 2) == 0;
            if (boo) {
                code += String.valueOf((int) (Math.random() * 10));
            } else {
                int temp = (int) (Math.random() * 2) == 0 ? 65 : 97;
                char ch = (char) (Math.random() * 26 + temp);
                code += String.valueOf(ch);
            }
        }
        return code;
    }

    public static void main(String[] args) {

        System.out.println(VerifyCode.getCode(6));
        System.out.println("-----------------");
        System.out.println(VerifyCode.getVerify(6));
    }

    public static String getVerify(int length) {
        String code = "";
        String str = "0123456789qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASFGHJKLZXCVBNM";
        String[] strs = str.split("");
        for (int i = 0; i < length; i++) {
            code += strs[(int) (Math.random() * strs.length)];
        }
        return code;
    }
}

package com.random;


import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Random;

public class Main {
      public static void main(String[] args) {
            //创建一个ArrayList集合，存放生成的代码
            List<Object> list = new ArrayList();
            //for循环生成6位验证码
            for(int i = 0;i<6;i++) {
                //if语句交替判断生成数字或者字母
                if(i%2==0) {
                    int b = (int)(Math.random()*10);//生成0~9的数字
                    list.add(b);
                }else {
                    boolean flag = false;
                    do {
                        int a = (int)(Math.random()*58+65);//生成大小写字母的ASCII码
                        //if排斥多余的中间其他字符
                        if(!(a>=91&&a<=95)) {
                            String s = (char)a+"";//数字转字母
                            list.add(s);
                            flag = true;
                        }
                    }while(!flag);
                }
            }
             Collections.shuffle(list);//shuffle随机排序
             String out = new String();
             for(Object s : list) {
                 out+=s;
             }
             System.out.println(out.toString());
        }
     
}