java - MD5 对相同的输入返回不同的值

Question

我在 Android 上，所以它只是 java，我有相同的输入字符串，但每次都得到不同的值。我错过了什么？谢谢

private String getShortenedKey(String key) {
        String shortenedKey=null;
        MessageDigest md = null;
        LogUtils.LOGD(HASH_ALGO, "before key: "+ System.currentTimeMillis());
        try {
            md = MessageDigest.getInstance("MD5");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
            shortenedKey = key;
        }
        LogUtils.LOGD(HASH_ALGO, "after key: "+ System.currentTimeMillis());

        md.update(key.getBytes());
        byte[] shortenedBytes = md.digest();
        shortenedKey = String.valueOf(shortenedBytes);
        return shortenedKey;
    }

输入字符串:

{"config":{"wp":"(1.000000,1.000000,1.000000,1.000000)","v":"8","unit":"auto","ef":true,"ws":1,"tt":0,"cs":1},"items":[{"startTime":1409180400,"id":"WorkXYZ@habit.skedgo.com_1409180400","class":"event","endTime":1409209200,"location":{"lng":151.20785,"lat":-33.85926},"priority":0},{"startTime":1409148000,"id":"HomeXYZ@habit.skedgo.com_1409148000","class":"event","endTime":1409234340,"location":{"lng":151.18089,"lat":-33.89153},"priority":0}]}

更新:这么多有效答案，谢谢。我选择最容易改变的那个。干杯。

Answer 1

这一行

shortenedKey = String.valueOf(shortenedBytes);

没有按照你的想法去做。

为了获得数组中字节值的字符串表示，您需要实现一些实用方法。

此外，如果对 MessageDigest.getInstance("MD5"); 的调用曾经抛出一个 NoSuchAlgorithmException，您的程序稍后会在此处崩溃 md.update (key.getBytes()); 与 NullPointerException。