java工具UTILS小合集（一）

/**
     * 根据日期获取星期
     *
     * @param strdate
     * @return
     */
    public static String getWeekDayByDate(String strdate) {
        final String dayNames[] = { "星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六" };
        SimpleDateFormat sdfInput = new SimpleDateFormat("yyyy-MM-dd");
        Calendar calendar = Calendar.getInstance();
        Date date = new Date();
        try {
            date = sdfInput.parse(strdate);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        calendar.setTime(date);
        int dayOfWeek = calendar.get(Calendar.DAY_OF_WEEK) - 1;
        if (dayOfWeek < 0)
            dayOfWeek = 0;
        return dayNames[dayOfWeek];
    }

/**
     * 判断是否是IE浏览器
     *
     * @param userAgent
     * @return
     */
    public static boolean isIE(HttpServletRequest request) {
        String userAgent = request.getHeader("USER-AGENT").toLowerCase();
        boolean isIe = true;
        int index = userAgent.indexOf("msie");
        if (index == -1) {
            isIe = false;
        }
        return isIe;
    }

/**
     * 基于MD5算法的单向加密
     *
     * @param strSrc
     *            明文
     * @return 返回密文
     */
    public static String encryptBasedMd5(String strSrc) {
        String outString = null;
        try {
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            byte[] outByte = md5.digest(strSrc.getBytes("UTF-8"));
            outString = outByte.toString();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return outString;
    }

/**
     * DES算法密钥
     */
    private static final byte[] DES_KEY = { 21, 1, -110, 82, -32, -85, -128, -65 };

    /**
     * 数据加密，算法（DES）
     *
     * @param data
     *            要进行加密的数据
     * @return 加密后的数据
     */
    public static String encryptBasedDes(String data) {
        String encryptedData = null;
        try {
            // DES算法要求有一个可信任的随机数源
            SecureRandom sr = new SecureRandom();
            DESKeySpec deskey = new DESKeySpec(DES_KEY);
            // 创建一个密匙工厂，然后用它把DESKeySpec转换成一个SecretKey对象
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
            SecretKey key = keyFactory.generateSecret(deskey);
            // 加密对象
            Cipher cipher = Cipher.getInstance("DES");
            cipher.init(Cipher.ENCRYPT_MODE, key, sr);
            // 加密，并把字节数组编码成字符串
            encryptedData = new Base64().encodeToString(cipher.doFinal(data.getBytes()));
        } catch (Exception e) {
            log.error("加密错误，错误信息：", e);
            throw new RuntimeException("加密错误，错误信息：", e);
        }
        return encryptedData;
    }

    /**
     * 数据解密，算法（DES）
     *
     * @param cryptData
     *            加密数据
     * @return 解密后的数据
     */
    public static String decryptBasedDes(String cryptData) {
        String decryptedData = null;
        try {
            // DES算法要求有一个可信任的随机数源
            SecureRandom sr = new SecureRandom();
            DESKeySpec deskey = new DESKeySpec(DES_KEY);
            // 创建一个密匙工厂，然后用它把DESKeySpec转换成一个SecretKey对象
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
            SecretKey key = keyFactory.generateSecret(deskey);
            // 解密对象
            Cipher cipher = Cipher.getInstance("DES");
            cipher.init(Cipher.DECRYPT_MODE, key, sr);
            // 把字符串解码为字节数组，并解密
            decryptedData = new String(cipher.doFinal(new Base64().decode(cryptData)));
        } catch (Exception e) {
            log.error("解密错误，错误信息：", e);
            throw new RuntimeException("解密错误，错误信息：", e);
        }
        return decryptedData;
    }