生成必须有大写小写和数字的随机字符串
public class Teee {
?public static void main(String[] args){
??System.out.println(snumber());
?}
?
// 生成必须有大写小写和数字的随机字符串?长度为9?
?public static? String snumber(){
??String num="";
??String[] str={"q","w","e","r","t","y","u","i"
????,"o","p","a","s","d","f","g","h","j"
????,"k","l","z","x","c","v","b","n","m"};
??for(int i=0;i<3;i++){
???int it1=(int)(Math.random()*25);
???int it2=(int)(Math.random()*25);
???int it3=new Random().nextInt(10);
???num+=str[it1]+str[it2].toUpperCase()+it3;
??}
??return num;
?}
}
