MD5（Message Digest Algorithm 5）是一种常用的哈希算法，用于将数据转换为固定长度的散列值。MD5算法将任意长度的数据作为输入，并生成一个128位（16字节）的散列值作为输出。

@Component
public class MD5Utils {

    private static EncryptProperties encryptProperties;

    @Autowired
    public MD5Utils(EncryptProperties encryptProperties) {
        MD5Utils.encryptProperties = encryptProperties;
    }

    public static String getEncryptPassword(String password) {
        String saltPassword = "{" + encryptProperties.getSalt() + "}" + password;
        MessageDigest MD5_DIGEST=null;
        try {
            MD5_DIGEST = MessageDigest.getInstance("MD5");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        for (int i = 0; i < encryptProperties.getRepeat(); i++) {
            saltPassword = Base64.getEncoder().encodeToString(MD5_DIGEST.digest(saltPassword.getBytes()));
        }
        return saltPassword;
    }
    /**
     * MD5加密（字符串部分非标准）
     * @param origin 原始字符串
     */
    @Deprecated
    public static String getEncryptPasswordNoSalt(String origin) {
        String resultString = null;
        try {
            resultString = origin;
            MessageDigest md = MessageDigest.getInstance("MD5");
            resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return resultString;
    }
    public static String byteArrayToHexString(byte[] b) {
        StringBuilder resultSb = new StringBuilder();
        for (byte aB : b) {
            resultSb.append(byteToHexString(aB));
        }
        return resultSb.toString();
    }
    /**
     * 转换byte到16进制
     * @param b 要转换的byte
     * @return 16进制格式
     */
    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0) {
            n = 256 + n;
        }
        int d1 = n / 16;  
        int d2 = n % 16;
        return hexDigits[d1] + hexDigits[d2];
    }
    private final static String[] hexDigits = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d",
            "e", "f" };
}