如何获得的Andr​​oid / Java中的文件目录的MD5校验 [英] How to get a file directory's MD5 checksum in Android/Java

问题描述

我希望得到一个文件目录的MD5校验，我已经得到一个文件的算法，但是当我用它到一个目录它导致空。我怎样才能快速得到检验。
以下是我的文件（从匿名stackoverflower编者）algotithm。

I want to get an MD5 checksum of a file directory, I have already get the algorithm for a file, but it results null when I use it to a directory. How can I get the checksum quickly. The following are my algotithm for a file(Edited from the anonymous stackoverflower).

public String fileToMD5(String filePath) {
        InputStream inputStream = null;
        try {
            inputStream = new FileInputStream(filePath); // Create an FileInputStream instance according to the filepath
            byte[] buffer = new byte[1024]; // The buffer to read the file
            MessageDigest digest = MessageDigest.getInstance("MD5"); // Get a MD5 instance
            int numRead = 0; // Record how many bytes have been read
            while (numRead != -1) {
                numRead = inputStream.read(buffer);
                if (numRead > 0)
                    digest.update(buffer, 0, numRead); // Update the digest
            }
            byte [] md5Bytes = digest.digest(); // Complete the hash computing
            return convertHashToString(md5Bytes); // Call the function to convert to hex digits
        } catch (Exception e) {
            return null;
        } finally {
            if (inputStream != null) {
                try {
                    inputStream.close(); // Close the InputStream
                } catch (Exception e) { }
            }
        }
    }

我搜索，有一些solutings：

I searched that there are some solutings:

1. pre-顺序目录下的文件。


2. 的COM preSS目录到为.zip或.rar程序存档文件等，并校验它。


3. 获取所有的目录到一个流中的内容，并校验它。

我不知道是否有一些方便的solutions.Thank你提前。

I wonder whether there are some convenient solutions.Thank you in advance.

推荐答案

据我所知，没有一个有效的方法来得到一个目录的校验和。

As far as I know there isn't an efficient way to get the checksum of a directory.

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