java实现的密码强度检测功能完整示例

本文实例讲述了java实现的密码强度检测功能。分享给大家供大家参考，具体如下：

CheckStrength.java文件：

package com.wx.pwd;
/**
 * 检测密码强度
 *
 * @author venshine
 */
public class CheckStrength {
  public enum LEVEL {
    EASY, MIDIUM, STRONG, VERY_STRONG, EXTREMELY_STRONG
  }
  /**
   * NUM 数字
   * SMALL_LETTER 小写字母
   * CAPITAL_LETTER 大写字母
   * OTHER_CHAR 特殊字符
   */
  private static final int NUM = 1;
  private static final int SMALL_LETTER = 2;
  private static final int CAPITAL_LETTER = 3;
  private static final int OTHER_CHAR = 4;
  /**
   * 简单的密码字典
   */
  private final static String[] DICTIONARY = {"password", "abc123", "iloveyou", "adobe123", "123123", "sunshine",
      "1314520", "a1b2c3", "123qwe", "aaa111", "qweasd", "admin", "passwd"};
  /**
   *检查字符类型，包括num、大写字母、小写字母和其他字符。
   *
   * @param c
   * @return
   */
  private static int checkCharacterType(char c) {
    if (c >= 48 && c <= 57) {
      return NUM;
    }
    if (c >= 65 && c <= 90) {
      return CAPITAL_LETTER;
    }
    if (c >= 97 && c <= 122) {
      return SMALL_LETTER;
    }
    return OTHER_CHAR;
  }
  /**
   * 按不同类型计算密码的数量
   *
   * @param passwd
   * @param type
   * @return
   */
  private static int countLetter(String passwd, int type) {
    int count = 0;
    if (null != passwd && passwd.length() > 0) {
      for (char c : passwd.toCharArray()) {
        if (checkCharacterType(c) == type) {
          count++;
        }
      }
    }
    return count;
  }
  /**
   * 检查密码的强度
   *
   * @param passwd
   * @return strength level
   */
  public static int checkPasswordStrength(String passwd) {
    if (StringUtils.equalsNull(passwd)) {
      throw new IllegalArgumentException("password is empty");
    }
    int len = passwd.length();
    int level = 0;
    // 增加点
    //判断密码是否含有数字有level++
    if (countLetter(passwd, NUM) > 0) {
      level++;
    }
    //判断密码是否含有小写字母有level++
    if (countLetter(passwd, SMALL_LETTER) > 0) {
      level++;
    }
    //判断密码是否还有大写字母有level++
    if (len > 4 && countLetter(passwd, CAPITAL_LETTER) > 0) {
      level++;
    }
    //判断密码是否还有特殊字符有level++
    if (len > 6 && countLetter(passwd, OTHER_CHAR) > 0) {
      level++;
    }
    //密码长度大于4并且2种类型组合......（不一一概述）
    if (len > 4 && countLetter(passwd, NUM) > 0 && countLetter(passwd, SMALL_LETTER) > 0
        || countLetter(passwd, NUM) > 0 && countLetter(passwd, CAPITAL_LETTER) > 0
        || countLetter(passwd, NUM) > 0 && countLetter(passwd, OTHER_CHAR) > 0
        || countLetter(passwd, SMALL_LETTER) > 0 && countLetter(passwd, CAPITAL_LETTER) > 0
        || countLetter(passwd, SMALL_LETTER) > 0 && countLetter(passwd, OTHER_CHAR) > 0
        || countLetter(passwd, CAPITAL_LETTER) > 0 && countLetter(passwd, OTHER_CHAR) > 0) {
      level++;
    }
    //密码长度大于6并且3中类型组合......（不一一概述）
    if (len > 6 && countLetter(passwd, NUM) > 0 && countLetter(passwd, SMALL_LETTER) > 0
        && countLetter(passwd, CAPITAL_LETTER) > 0 || countLetter(passwd, NUM) > 0
        && countLetter(passwd, SMALL_LETTER) > 0 && countLetter(passwd, OTHER_CHAR) > 0
        || countLetter(passwd, NUM) > 0 && countLetter(passwd, CAPITAL_LETTER) > 0
        && countLetter(passwd, OTHER_CHAR) > 0 || countLetter(passwd, SMALL_LETTER) > 0
        && countLetter(passwd, CAPITAL_LETTER) > 0 && countLetter(passwd, OTHER_CHAR) > 0) {
      level++;
    }
    //密码长度大于8并且4种类型组合......（不一一概述）
    if (len > 8 && countLetter(passwd, NUM) > 0 && countLetter(passwd, SMALL_LETTER) > 0
        && countLetter(passwd, CAPITAL_LETTER) > 0 && countLetter(passwd, OTHER_CHAR) > 0) {
      level++;
    }
    //密码长度大于6并且2种类型组合每种类型长度大于等于3或者2......（不一一概述）
    if (len > 6 && countLetter(passwd, NUM) >= 3 && countLetter(passwd, SMALL_LETTER) >= 3
        || countLetter(passwd, NUM) >= 3 && countLetter(passwd, CAPITAL_LETTER) >= 3
        || countLetter(passwd, NUM) >= 3 && countLetter(passwd, OTHER_CHAR) >= 2
        || countLetter(passwd, SMALL_LETTER) >= 3 && countLetter(passwd, CAPITAL_LETTER) >= 3
        || countLetter(passwd, SMALL_LETTER) >= 3 && countLetter(passwd, OTHER_CHAR) >= 2
        || countLetter(passwd, CAPITAL_LETTER) >= 3 && countLetter(passwd, OTHER_CHAR) >= 2) {
      level++;
    }
    //密码长度大于8并且3种类型组合每种类型长度大于等于3或者2......（不一一概述）
    if (len > 8 && countLetter(passwd, NUM) >= 2 && countLetter(passwd, SMALL_LETTER) >= 2
        && countLetter(passwd, CAPITAL_LETTER) >= 2 || countLetter(passwd, NUM) >= 2
        && countLetter(passwd, SMALL_LETTER) >= 2 && countLetter(passwd, OTHER_CHAR) >= 2
        || countLetter(passwd, NUM) >= 2 && countLetter(passwd, CAPITAL_LETTER) >= 2
        && countLetter(passwd, OTHER_CHAR) >= 2 || countLetter(passwd, SMALL_LETTER) >= 2
        && countLetter(passwd, CAPITAL_LETTER) >= 2 && countLetter(passwd, OTHER_CHAR) >= 2) {
      level++;
    }
    //密码长度大于10并且4种类型组合每种类型长度大于等于2......（不一一概述）
    if (len > 10 && countLetter(passwd, NUM) >= 2 && countLetter(passwd, SMALL_LETTER) >= 2
        && countLetter(passwd, CAPITAL_LETTER) >= 2 && countLetter(passwd, OTHER_CHAR) >= 2) {
      level++;
    }
    //特殊字符>=3 level++;
    if (countLetter(passwd, OTHER_CHAR) >= 3) {
      level++;
    }
    //特殊字符>=6 level++;
    if (countLetter(passwd, OTHER_CHAR) >= 6) {
      level++;
    }
    //长度>12 >16 level++
    if (len > 12) {
      level++;
      if (len >= 16) {
        level++;
      }
    }
    // 减少点
    if ("abcdefghijklmnopqrstuvwxyz".indexOf(passwd) > 0 || "ABCDEFGHIJKLMNOPQRSTUVWXYZ".indexOf(passwd) > 0) {
      level--;
    }
    if ("qwertyuiop".indexOf(passwd) > 0 || "asdfghjkl".indexOf(passwd) > 0 || "zxcvbnm".indexOf(passwd) > 0) {
      level--;
    }
    if (StringUtils.isNumeric(passwd) && ("01234567890".indexOf(passwd) > 0 || "09876543210".indexOf(passwd) > 0)) {
      level--;
    }
    if (countLetter(passwd, NUM) == len || countLetter(passwd, SMALL_LETTER) == len
        || countLetter(passwd, CAPITAL_LETTER) == len) {
      level--;
    }
    if (len % 2 == 0) { // aaabbb
      String part1 = passwd.substring(0, len / 2);
      String part2 = passwd.substring(len / 2);
      if (part1.equals(part2)) {
        level--;
      }
      if (StringUtils.isCharEqual(part1) && StringUtils.isCharEqual(part2)) {
        level--;
      }
    }
    if (len % 3 == 0) { // ababab
      String part1 = passwd.substring(0, len / 3);
      String part2 = passwd.substring(len / 3, len / 3 * 2);
      String part3 = passwd.substring(len / 3 * 2);
      if (part1.equals(part2) && part2.equals(part3)) {
        level--;
      }
    }
    if (StringUtils.isNumeric(passwd) && len >= 6) { // 19881010 or 881010
      int year = 0;
      if (len == 8 || len == 6) {
        year = Integer.parseInt(passwd.substring(0, len - 4));
      }
      int size = StringUtils.sizeOfInt(year);
      int month = Integer.parseInt(passwd.substring(size, size + 2));
      int day = Integer.parseInt(passwd.substring(size + 2, len));
      if (year >= 1950 && year < 2050 && month >= 1 && month <= 12 && day >= 1 && day <= 31) {
        level--;
      }
    }
    if (null != DICTIONARY && DICTIONARY.length > 0) {// dictionary
      for (int i = 0; i < DICTIONARY.length; i++) {
        if (passwd.equals(DICTIONARY[i]) || DICTIONARY[i].indexOf(passwd) >= 0) {
          level--;
          break;
        }
      }
    }
    if (len <= 6) {
      level--;
      if (len <= 4) {
        level--;
        if (len <= 3) {
          level = 0;
        }
      }
    }
    if (StringUtils.isCharEqual(passwd)) {
      level = 0;
    }
    if (level < 0) {
      level = 0;
    }
    return level;
  }
  /**
   *获得密码强度等级，包括简单、复杂、强、强、强
   *
   * @param passwd
   * @return
   */
  public static LEVEL getPasswordLevel(String passwd) {
    int level = checkPasswordStrength(passwd);
    switch (level) {
      case 0:
      case 1:
      case 2:
      case 3:
        return LEVEL.EASY;
      case 4:
      case 5:
      case 6:
        return LEVEL.MIDIUM;
      case 7:
      case 8:
      case 9:
        return LEVEL.STRONG;
      case 10:
      case 11:
      case 12:
        return LEVEL.VERY_STRONG;
      default:
        return LEVEL.EXTREMELY_STRONG;
    }
  }
}

StringUtils.java文件：

package com.wx.pwd;
/**
 * 字符串工具类
 *
 * @author venshine
 */
public class StringUtils {
  private final static int[] SIZE_TABLE = {9, 99, 999, 9999, 99999, 999999, 9999999, 99999999, 999999999,
      Integer.MAX_VALUE};
  /**
   * 计算一个整数的大小
   *
   * @param x
   * @return
   */
  public static int sizeOfInt(int x) {
    for (int i = 0; ; i++)
      if (x <= SIZE_TABLE[i]) {
        return i + 1;
      }
  }
  /**
   * 判断字符串的每个字符是否相等
   *
   * @param str
   * @return
   */
  public static boolean isCharEqual(String str) {
    return str.replace(str.charAt(0), ' ').trim().length() == 0;
  }
  /**
   * 确定字符串是否为数字
   *
   * @param str
   * @return
   */
  public static boolean isNumeric(String str) {
    for (int i = str.length(); --i >= 0; ) {
      if (!Character.isDigit(str.charAt(i))) {
        return false;
      }
    }
    return true;
  }
  /**
   * 判断字符串是否为空格、空(“)”或null。
   *
   * @param str
   * @return
   */
  public static boolean equalsNull(String str) {
    int strLen;
    if (str == null || (strLen = str.length()) == 0 || str.equalsIgnoreCase("null")) {
      return true;
    }
    for (int i = 0; i < strLen; i++) {
      if ((Character.isWhitespace(str.charAt(i)) == false)) {
        return false;
      }
    }
    return true;
  }
}

CheckPWD.java文件：

package com.wx.pwd;
public class CheckPWD {
 public static void main(String[] args) {
    String passwd = "myNameJOB123_-+=";
    System.out.println(CheckStrength.checkPasswordStrength(passwd));
    System.out.println(CheckStrength.getPasswordLevel(passwd));
  }
}

运行结果：

13
EXTREMELY_STRONG

PS：这里再为大家提供两款功能类似的在线工具供大家参考：

密码安全性在线检测：
http://tools.jb51.net/password/my_password_safe

高强度密码生成器：
http://tools.jb51.net/password/CreateStrongPassword

在线随机数字/字符串生成工具：
http://tools.jb51.net/aideddesign/suijishu

更多关于java算法相关内容感兴趣的读者可查看本站专题：《Java数据结构与算法教程》、《Java字符与字符串操作技巧总结》、《Java操作DOM节点技巧总结》、《Java文件与目录操作技巧汇总》和《Java缓存操作技巧汇总》

希望本文所述对大家java程序设计有所帮助。