The following error was reported by a user of Aptana which uses 0.2.7 version of j2ssh. It doesn't look like this class has changed so the error should still be there. The NoSuchElementException isn't caught in this constructor although others are.
For more information: http://www.aptana.com/trac/ticket/4776
java.util.NoSuchElementException?
at java.util.StringTokenizer?.nextToken(StringTokenizer?.java:332) at java.util.StringTokenizer?.nextElement(StringTokenizer?.java:390) at com.sshtools.j2ssh.transport.AbstractKnownHostsKeyVerification?.<init>(AbstractKnownHostsKeyVerification?.java:116) at com.sshtools.j2ssh.transport.ConsoleKnownHostsKeyVerification?.<init>(ConsoleKnownHostsKeyVerification?.java:62)
This is caused by blank or malformed lines in the known_hosts file. The parser should be written to fix this.