Modern Linux installations no longer provide MD5 SSH fingerprints by default.
Therefore I implemented some code for replacing calls like

sshClient.addHostKeyVerifier("4b:69:6c:72:6f:79:20:77:61:73:20:68:65:72:65:21");.

Using the helper class from the following GIST it is possible to write:

sshClient.addHostKeyVerifier(SSHFingerprintVerifier.getInstance("SHA1:<base64 encoded fingerprint>"));

SHA-256 and the old MD5 (no prefix, just the old hex notation) are supported as well.