Apache Mina SSHD 1.0 Server exits immediately

I am using Apache Mina sshd-core-1.0.0 to start an SFTP daemon. The program however exits after the sshd.start(). There are no errors. However if I use sshd-core-0.0.14, the server starts just fine and I can initiate an SFTP session. Am I missing something with 1.0.0?

Code snippet with 1.0.0 (does not work)

public static void main(String[] args) throws IOException {
    SshServer sshd = SshServer.setUpDefaultServer();
    sshd.setPort(2222);
    sshd.setKeyPairProvider(new SimpleGeneratorHostKeyProvider(new File ("hostkey.ser")))   
    sshd.setPasswordAuthenticator(new AuthenticatorImpl());
    sshd.start();
}

Code snippet with 0.0.14 (works)

public static void main(String[] args) throws IOException {
    SshServer sshd = SshServer.setUpDefaultServer();
    sshd.setPort(2222);
    sshd.setKeyPairProvider(new SimpleGeneratorHostKeyProvider("hostkey.ser")); 
    sshd.setPasswordAuthenticator(new AuthenticatorImpl());
    sshd.start();
}

The following is output when 1.0.0 runs. The code starts fine but terminates after the sshd.start() statement.

2015-12-16 19:57:38,510 DEBUG SFTPServer.main(SFTPServer.java:26) message
2015-12-16 19:57:38,767 INFO org.apache.sshd.common.util.SecurityUtils$BouncyCastleRegistration.call(SecurityUtils.java:145) Trying to register BouncyCastle as a JCE provider
2015-12-16 19:57:39,076 INFO org.apache.sshd.common.util.SecurityUtils$BouncyCastleRegistration.call(SecurityUtils.java:149) Registration succeeded
2015-12-16 19:57:39,105 DEBUG org.apache.sshd.common.io.nio2.Nio2Acceptor.bind(Nio2Acceptor.java:57) Binding Nio2Acceptor to address 0.0.0.0/0.0.0.0:2222
2015-12-16 19:57:39,114 INFO SFTPServer.main(SFTPServer.java:32) Started

Solution

The SshServer.Start only starts listening on the incoming port. It does not block. So the main is terminated immediately afterwards. This should not be any different in 0.0.14, though I cannot try.

You have to wait in the main explicitly to keep the server running.

See how SshServer.main is implemented (both in 0.0.14 and 1.0.0):

public static void main(String[] args) throws Exception {

    ...

    SshServer sshd = SshServer.setUpDefaultServer();

    ...

    sshd.start();

    Thread.sleep(Long.MAX_VALUE);
}