public static void main(String[] args) {
//调用方法
String code = creatCode(5);
System.out.println("生成的验证:" + code);
}
public static String creatCode(int n){
String code = "";
Random r = new Random();
//定义一个for循环,循环n次,依次生成随机字符
for (int i = 0; i < n; i++) {
//生成一个随机字符,字母大写,字母小写,数字
int type = r.nextInt(3);
switch (type){
case 0:
char ch = (char) (r.nextInt(26)+65);
code += ch;
break;
case 1:
char ch1 = (char) (r.nextInt(26) + 97);
code += ch1;
break;
case 2:
code += r.nextInt(10);
break;
}
}
return code;
}
方法二
public static void main(String[] args) {
String datas = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRXTUVWXYZ0123456789";
String verCode = "";
//生成随机数
Random r = new Random();
for (int i = 0; i < 5; i++) {
//随机一个索引
int index = r.nextInt(datas.length());
//获取某个索引处的字符
char c = datas.charAt(index);
verCode += c;
}
//输出字符串变量
System.out.println(verCode);
}