Java Requires Chilkat v11.0.0+

IMAP Use Existing SSH Tunnel

Demonstrates how to connect to an IMAP server using an existing SSH tunnel. This creates a new channel within the SSH tunnel, which can be a TCP or TLS connection, and is connected to a remote IMAP server through port forwarding. Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Email;
import com.chilkatsoft.chilkat2.Imap;
import com.chilkatsoft.chilkat2.Socket;

public class ChilkatExample {

    public static void main(String[] args) {
        // This example assumes the Chilkat API to have been previously unlocked.
        // See Global Unlock Sample for sample code.

        Socket tunnel = new Socket();

        String sshHostname = "sftp.example.com";
        int sshPort = 22;

        // Connect to an SSH server and establish the SSH tunnel:
        try {
            tunnel.sshOpenTunnel(sshHostname, sshPort);

            // Authenticate with the SSH server via a login/password
            // or with a public key.
            // This example demonstrates SSH password authentication.
            // Note: This is not authenticating with the IMAP server, it is
            // for authenticating with the SSH server, which is separate.
            tunnel.sshAuthenticatePw("mySshLogin", "mySshPassword");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // OK, the SSH tunnel is setup.  Now open a channel within the tunnel.
        // Once the channel is obtained, the Socket API may
        // be used exactly the same as usual, except all communications
        // are sent through the channel in the SSH tunnel.
        // Any number of channels may be created from the same SSH tunnel.
        // Multiple channels may coexist at the same time.

        Imap imap = new Imap();

        // Let the IMAP object also use the SSH tunnel
        try {
            imap.useSshTunnel(tunnel);

            // Connect to an IMAP server via the already established SSH tunnel.
            // Because the SSH tunnel has been previously setup,
            // this does not establish a direct connection with the IMAP
            // server.  It directs the SSH server to establish the connection.

            // In this example, the IMAP server requires SSL/TLS.  The TLS connection
            // will be enclosed within the SSH tunnel.
            imap.setSsl(true);
            imap.setPort(993);
            imap.connect("imap.my-imap-server.com");

            // Authenticate with the IMAP server via the SSH tunnel.
            imap.login("myLogin", "myPassword");

            // Select an IMAP mailbox
            imap.selectMailbox("Inbox");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // How many messages in Inbox?
        int msgCount = imap.getNumMessages();
        if (msgCount == 0) {
            System.out.println("No messages found.");
            return;
        }

        int upperBound = 10;
        if (msgCount < upperBound) {
            upperBound = msgCount;
        }

        // Download up to the 1st 10 messages.
        Email email = new Email();
        boolean bUid = false;
        for (int i = 1; i <= upperBound; i++) {
            try {
                imap.fetchEmail(false, i, bUid, email);
            } catch (ChilkatException e) {
                System.out.println(e.getLastErrorText());
                return;
            }

            System.out.println(email.getFrom());
            System.out.println(email.getSubject());
        }

        // Disconnect from the IMAP server.
        // The SSH tunnel remains open.
        try {
            imap.disconnect();

            // It is possible to re-use the existing SSH tunnel for the next connection:
            imap.connect("imap.my-imap-server2.com");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Review the LastErrorText to see that the connection was made via the SSH tunnel:
        System.out.println(imap.getLastErrorText());

        // This closes the SSH channel, which is the connection with the IMAP server.
        // It does not close the SSH tunnel
        try {
            imap.disconnect();

            // Finally, close the SSH tunnel.

            // Note: If other objects are using the same SSH tunnel, the tunnel is not
            // actually closed.  It is only closed when the last object using the tunnel closes it.

            // At this point, both the imap and tunnel objects have references to the internal
            // SSH tunnel.  We need to close each.

            // This call doesn't actually close the tunnel yet, because the tunnel object still
            // holds an internal reference.
            imap.sshCloseTunnel();

            // This actually closes the SSH tunnel because it's the last object using it.
            tunnel.sshCloseTunnel();
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("IMAP pre-existing SSH tunnel example completed.");
    }
}