详解SpringBoot实现fastdfs防盗链功能的示例代码

# true 表示开启防盗链
http.anti_steal.check_token = true
# token的过期时间，单位为秒
http.anti_steal.token_ttl = 60
# 密钥，不可泄漏，用于生成token
http.anti_steal.secret_key = thisisasecuritykey
# 当图片拒绝访问后，显示的图片，此图片需要可访问，不然可能会出现问题
http.anti_steal.token_check_fail = /data/fastdfs/401.jpg

group1/M00/00/00/wKh5iWNBl7-AKvj1AAAwWD4VeAg577.jpg
`需要替换成`
M00/00/00/wKh5iWNBl7-AKvj1AAAwWD4VeAg577.jpg

/**
     * 生成token
     *
     * @param fileId          the filename return by FastDFS server,不能含有组
     * @param timestampSecond 时间戳 单位秒
     * @return token
     * @throws NoSuchAlgorithmException
     */
    private String generatorToken(String fileId, Long timestampSecond) throws NoSuchAlgorithmException {
        // 需要去掉 group
        fileId = fileId.substring(fileId.indexOf("/") + 1);
        byte[] bsFilename = fileId.getBytes(StandardCharsets.UTF_8);
        byte[] bsTimestamp = timestampSecond.toString().getBytes(StandardCharsets.UTF_8);
        // thisisasecuritykey 需要和 /etc/fdfs/http.conf 中的 http.anti_steal.secret_key 值一致
        byte[] bsKey = "thisisasecuritykey".getBytes(StandardCharsets.UTF_8);

        byte[] buff = new byte[bsFilename.length + bsKey.length + bsTimestamp.length];
        System.arraycopy(bsFilename, 0, buff, 0, bsFilename.length);
        System.arraycopy(bsKey, 0, buff, bsFilename.length, bsKey.length);
        System.arraycopy(bsTimestamp, 0, buff, bsFilename.length + bsKey.length, bsTimestamp.length);

        return md5(buff);
    }

    public static String md5(byte[] source) throws NoSuchAlgorithmException {
        char hexDigits[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
        java.security.MessageDigest md = java.security.MessageDigest.getInstance("MD5");
        md.update(source);
        byte tmp[] = md.digest();
        char str[] = new char[32];
        int k = 0;
        for (int i = 0; i < 16; i++) {
            str[k++] = hexDigits[tmp[i] >>> 4 & 0xf];
            str[k++] = hexDigits[tmp[i] & 0xf];
        }

        return new String(str);
    }