java字符串乱序
public static String disorderString(String str) {
List<String> list = Arrays.asList(str.split(""));
Collections.shuffle(list);
String out = new String();
for (String s : list) {
out += s;
}
return out;
}
//字符串中检出n个字符
public static String pickRandomString(String str, int length) {
String strChaos = disorderString(str);
return strChaos.substring(0, length);
}