Problem Statement

Encode a string using an MD5 algorithm.   The algorithm can be found on   Wikipedia.

Optionally, validate your implementation by running all of the test values in   IETF RFC (1321)   for MD5. Additionally,   RFC 1321   provides more precise information on the algorithm than the Wikipedia article. If the solution on this page is a library solution, see   MD5/Implementation   for an implementation from scratch.

Let's start with the solution:

import java.security.MessageDigest

String.metaClass.md5Checksum = {
    MessageDigest.getInstance('md5').digest(delegate.bytes).collect { String.format("%02x", it) }.join('')
}


assert 'The quick brown fox jumps over the lazy dog'.md5Checksum() == '9e107d9d372bb6826bd81d3542a419d6'