随机生成6位包含数字大小写字母的验证码

package week;
/**
* 26为字母
* 十二位数字
*
*/
public class AllCharacter {
public static char[] charArray() {
int i = 1234567890;
String s = "qwertyuiopasdfghjklzxcvbnm";
String S = s.toUpperCase();
String word = s+S+i;
char[] c =word.toCharArray();
return c;
}

}

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测试类

package week;

import java.util.Random;

public class Test3 {
public static void main(String[] args) {
for(int i=0; i<6;i++) {
String s = verifyCode();
System.out.println(s);
}
}
public static String verifyCode() {
char[] c = AllCharacter.charArray();
Random rd = new Random();
String code="";
for (int k = 0; k < 6; k++) {
int index = rd.nextInt(c.length);//随机获取数组长度作为索引
code+=c[index];//循环添加到字符串后面
}
return code;
}

}