I am trying to match the md5sum of a downloaded file from server. Processing will be continued only if sums match.
try {
MessageDigest digest = MessageDigest.getInstance("MD5");
File f = new File(fileName);
InputStream is = new FileInputStream(f);
byte[] buffer = new byte[8192];
int read = 0;
while( (read = is.read(buffer)) > 0) {
digest.update(buffer, 0, read);
}
is.close();
byte[] md5sum = digest.digest();
BigInteger bigInt = new BigInteger(1, md5sum);
output = bigInt.toString(16);
System.out.println("MD5: " + output);
} catch(IOException e) {
throw new RuntimeException("Unable to process file for MD5", e);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
Above code doesn't provide the md5sum properly for some files every time.
When i go to console and check md5sum <filename> md5sum is same as that in server. But when same is calculated from code it is yielding a different result.
vimdiff of downloaded file is not providing any diff.. The files are proper after download.
I am unable to see a problem in above code.
I am trying to change the buffer size. But no luck, So i am guessing that it is not because of the buffer size etc.
byte[] buffer = new byte[8192];
Regards
Dheeraj Joshi
BigInteger.toString method will escape the leading 0's as they are not important.