public class JChannel ...
{
  // Initialization can accept either options or configuration file
  public JChannel (String props) throws Exception;

  // Join a group with a given name
  public void connect (String cluster) throws Exception;
  public void disconnect ();

  // View is the current list of members
  public View getView ();

  public void send (Message msg) throws Exception;
  public void send (Address dst, byte[] buf) throws Exception;
  public void send (Address dst, Serializable obj) throws Exception;
  public void receive (Message msg);

  // Asynchronous notification about messages and membership is available
  public void setReceiver (Receiver r);

  ...
}

public interface MessageListener
{
  void receive (Message msg);

  // Group members can share state
  void getState (OutputStream output) throws Exception;
  void setState(InputStream input) throws Exception;
}

public interface MembershipListener
{
  // Notification about membership view change
  public void viewAccepted (View view);

  // Indication of suspect member before actual removal
  public void suspect (Object suspected);

  // Notifies about temporary suspension during view update
  public void block ();
  public void unblock ();
}

public interface Receiver extends MessageListener, MembershipListener;