MD5相关使用

我们在日常开发中，不管是密码加密亦或者文件取md5值，都会用到Md5，下面就给出了这两种使用情况

一、使用md5进行密码加密

/**
     * MD5加密
     *
     * @param password 要加密的值
     * @param salt 密码的"盐"
     * @return
     */
    public static String encode(String password, String salt) {
        password = password + salt;
        MessageDigest md5 = null;
        try {
            md5 = MessageDigest.getInstance("MD5");
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        char[] charArray = password.toCharArray();
        byte[] byteArray = new byte[charArray.length];
        for (int i = 0; i < charArray.length; i++)
            byteArray[i] = (byte) charArray[i];
        byte[] md5Bytes = md5.digest(byteArray);
        StringBuffer hexValue = new StringBuffer();
        for (int i = 0; i < md5Bytes.length; i++) {
            int val = ((int) md5Bytes[i]) & 0xff;
            if (val < 16) {
                hexValue.append("0");
            }
            hexValue.append(Integer.toHexString(val));
        }
        return hexValue.toString();
    }

二、文件类取md5

 /**
     * 文件类取MD5
     *
     * @param file
     * @return
     */
    public static String fileMD5(File file) {
        try (InputStream stream = Files.newInputStream(file.toPath(), StandardOpenOption.READ)) {
            return streamMD5(stream);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }


    /**
     * 输入流取MD5
     *
     * @param stream
     * @return
     */
    public static String streamMD5(InputStream stream) {
        MessageDigest md5 = null;
        byte[] byteArray = null;
        try {
            md5 = MessageDigest.getInstance("MD5");
            byteArray = toByteArray(stream);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        byte[] md5Bytes = md5.digest(byteArray);
        StringBuffer hexValue = new StringBuffer();
        for (int i = 0; i < md5Bytes.length; i++) {
            int val = ((int) md5Bytes[i]) & 0xff;
            if (val < 16) {
                hexValue.append("0");
            }
            hexValue.append(Integer.toHexString(val));
        }
        return hexValue.toString();
    }

    public static byte[] toByteArray(InputStream input) throws IOException {
        ByteArrayOutputStream output = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024 * 4];
        int n = 0;
        while (-1 != (n = input.read(buffer))) {
            output.write(buffer, 0, n);
        }
        return output.toByteArray();
    }

暂时只有这两个，后续更新......