生成随机数问题

[ionlic]

有的网站会在你注册之后（注册过程仅仅是填写email和用户id），
给你发送你的注册密码。

这个密码一般是数字+字母的组合。这个是怎么实现的呢？望达人指教。谢谢

[umbrella1984]

String s="";
String arrykey[]={"0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
Random x=new Random();

for(int i=1;i<=6;i++){
String temp=null;
int tempnum=x.nextInt(35);
temp=arrykey[tempnum];
s=s+temp;
}
System.out.println(s);

[ChDw]

static char[] PWD_CHAR = new char []{
'0','1','2','3',.... .......,'z'
};

public String genPwd() {
StringBuffer sb = new StringBuffer();
Random rand = new Random();
for(int i = 0; i < MAX_LEN; i++) {
sb.append(PWD_CHAR[rand.nextInt(PWD_CHAR.length)]);
}
return sb.toString();
}