Java密码强度校验：正确检测字符串中的特殊字符、数字和字母的方法

char[] specialChars = "!@#*+-_(%?/{}[].,;:".toCharArray();
for (int i = 0; i < specialChars.length; i++) {
    if (Password.indexOf(specialChars[i]) > -1) {
        System.out.println(esitoPositivospeciale);
    } else {
        throw new MissingSpecialCharacterException();
    }
}

for (int n = 0; n < Password.length(); n++) {
    if (Password.substring(n).matches(".*[a-z].*")) {
        System.out.println(esitoPositivocarattere);
    } else {
        throw new MissingCharacterException();
    }
    // ... 对数字的检查也类似
}

boolean foundSpecial = false;
char[] specialChars = "!@#*+-_(%?/{}[].,;:".toCharArray();
for (char sc : specialChars) { // 遍历定义的特殊字符
    if (Password.indexOf(sc) > -1) { // 检查密码中是否包含当前特殊字符
        foundSpecial = true; // 如果找到，设置标志为true
        break; // 找到一个即可，无需继续遍历
    }
}
if (foundSpecial) {
    System.out.println("特殊字符已包含。");
} else {
    throw new MissingSpecialCharacterException();
}

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class PasswordValidator {

    private static final String SPECIAL_CHARS_SET = "!@#*+-_(%?/{}[].,;:";

    // 编译正则表达式模式，提高效率
    private static final Pattern LETTER_PATTERN = Pattern.compile(".*[a-zA-Z].*");
    private static final Pattern DIGIT_PATTERN = Pattern.compile(".*\d.*");
    private static final Pattern SPECIAL_CHAR_PATTERN = Pattern.compile(".*[" + Pattern.quote(SPECIAL_CHARS_SET) + "].*");

    public static void validatePassword(String password) 
            throws MissingCharacterException, MissingNumberException, MissingSpecialCharacterException {

        if (password == null || password.isEmpty()) {
            throw new IllegalArgumentException("密码不能为空。");
        }

        // 检查是否包含字母
        Matcher letterMatcher = LETTER_PATTERN.matcher(password);
        if (!letterMatcher.matches()) {
            throw new MissingCharacterException("密码缺少字母。");
        }

        // 检查是否包含数字
        Matcher digitMatcher = DIGIT_PATTERN.matcher(password);
        if (!digitMatcher.matches()) {
            throw new MissingNumberException("密码缺少数字。");
        }

        // 检查是否包含特殊字符
        Matcher specialCharMatcher = SPECIAL_CHAR_PATTERN.matcher(password);
        if (!specialCharMatcher.matches()) {
            throw new MissingSpecialCharacterException("密码缺少特殊字符。");
        }

        System.out.println("密码符合要求：包含字母、数字和特殊字符。");
    }

    // 自定义异常类
    static class MissingSpecialCharacterException extends Exception {
        public MissingSpecialCharacterException(String message) { super(message); }
    }

    static class MissingNumberException extends Exception {
        public MissingNumberException(String message) { super(message); }
    }

    static class MissingCharacterException extends Exception {
        public MissingCharacterException(String message) { super(message); }
    }

    public static void main(String[] args) {
        String testPassword1 = "Abc123!"; // 符合要求
        String testPassword2 = "Abc123";  // 缺少特殊字符
        String testPassword3 = "Abc!!";   // 缺少数字
        String testPassword4 = "123!!";   // 缺少字母
        String testPassword5 = "";        // 空密码

        System.out.println("--- 测试密码: " + testPassword1 + " ---");
        try {
            validatePassword(testPassword1);
        } catch (Exception e) {
            System.out.println("校验失败: " + e.getMessage());
        }

        System.out.println("
--- 测试密码: " + testPassword2 + " ---");
        try {
            validatePassword(testPassword2);
        } catch (Exception e) {
            System.out.println("校验失败: " + e.getMessage());
        }

        System.out.println("
--- 测试密码: " + testPassword3 + " ---");
        try {
            validatePassword(testPassword3);
        } catch (Exception e) {
            System.out.println("校验失败: " + e.getMessage());
        }

        System.out.println("
--- 测试密码: " + testPassword4 + " ---");
        try {
            validatePassword(testPassword4);
        } catch (Exception e) {
            System.out.println("校验失败: " + e.getMessage());
        }

        System.out.println("
--- 测试密码: " + testPassword5 + " ---");
        try {
            validatePassword(testPassword5);
        } catch (Exception e) {
            System.out.println("校验失败: " + e.getMessage());
        }
    }
}