第一次接触Collections类的shuffle用法,记得当时还特意去查看了jdk说明文档。该方法是打乱集合里的顺序,如针对List等。
以下是我的测试类,模拟获取电话号码:
public static String generateCellPhoneValNum() {
String[] beforeShuffle = new String[]{"1", "2", "3", "4", "5", "6",
"7", "8", "9", "0"};
List<String> list = Arrays.asList(beforeShuffle);
Collections.shuffle(list);
StringBuilder buffer = new StringBuilder();
for (int i = 0; i < list.size(); i++) {
buffer.append(list.get(i));
}
String afterShuffle = buffer.toString();
String result = afterShuffle.substring(3, 9);
return result;
}
随机的获取6位字符串的值,该实现思路可以运用在数据库自定义主键等范畴。