// 获取随机字符串
public static String getRandomString(int length) { // length 字符串长度
StringBuffer buffer = new StringBuffer("abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ");
StringBuffer sb = new StringBuffer();
Random r = new Random();
int range = buffer.length();
for (int i = 0; i < length; i++) {
sb.append(buffer.charAt(r.nextInt(range)));
}
return sb.toString();
}