Java生成满足正则表达式的随机密码

r囧r小猫 2022-02-02 00:39 454阅读 0赞

生成随机密码，密码至少要包含 大写字母，小写字母，数字，特殊字符四者中的三种组合，并且不能包含中文，还要满足线程安全。

代码如下：

public class PasswordGenerator {
    
      private static final char[] CHARR = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890~!@#$%^&*.?-+=_"
          .toCharArray();
      private static final String PASSWORD_REGEX = "^(?![a-zA-Z]+$)(?![A-Z0-9]+$)(?![A-Z\\W_!@#$%^&*`~()-+=]+$)(?![a-z0-9]+$)(?![a-z\\W_!@#$%^&*`~()-+=]+$)(?![0-9\\W_!@#$%^&*`~()-+=]+$)[a-zA-Z0-9\\W_!@#$%^&*`~()-+=]{8,16}$";
      private static final String NO_CHINESE_REGEX = "^[^\\u4e00-\\u9fa5]+$";
      private static final Pattern PASSWORD_PATTERN = Pattern.compile(PASSWORD_REGEX);
      private static final Pattern NO_CHINESE_PATTERN = Pattern.compile(NO_CHINESE_REGEX);
    
      public static String generatePassword(int length) {
        length = length < 8 ? 8 : length;
        length = length > 16 ? 16 : length;
        String result = getRandomPassword(length);
        Matcher m = PASSWORD_PATTERN.matcher(result);
        Matcher m1 = NO_CHINESE_PATTERN.matcher(result);
        if (m.matches() && m1.matches()) {
          return result;
        }
        return generatePassword(length);
      }
    
      private static String getRandomPassword(int length) {
        StringBuilder sb = new StringBuilder();
        ThreadLocalRandom r = ThreadLocalRandom.current();
        for (int x = 0; x < length; ++x) {
          sb.append(CHARR[r.nextInt(CHARR.length)]);
        }
        return sb.toString();
      }
    }

为了实现线程安全，这里用到了ThreadLocalRandom，而非Random。保证了高并发场景下密码随机性。

密码的正则表达式以及js测试代码如下，可通过F12验证，当前正则指定了字符串长度为8-16位，你可以根据实际需求略做调整。

var pattern = /^(?![a-zA-Z]+$)(?![A-Z0-9]+$)(?![A-Z\W_!@#$%^&*`~()-+=]+$)(?![a-z0-9]+$)(?![a-z\W_!@#$%^&*`~()-+=]+$)(?![0-9\W_!@#$%^&*`~()-+=]+$)[a-zA-Z0-9\W_!@#$%^&*`~()-+=]{8,16}$/;
    console.log("匹配吗："+pattern.test("Pas33332w0rd"));