Listening for events
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For an object to listen for events published by the Telnet class the following steps are required:

1. Set object to implement
TelnetListener or extend TelnetAdapter class.
2. Overload event handling methods.
3. Subscribe object to receive events published by
Telnet instance.

The
TelnetListener class is a pure interface and can be used in cases where the class you defined to listen for events already extends another class type. The TelnetAdapter class implements the TelnetListener interface and can be used in cases where there is no need for class inheritance.

Note


Unless your class requires inheritance it is generally easier to use the TelnetAdapter class as it provides default implementations for all the event handler methods defined in the TelnetListener interface. This allows you to overload only the event handler methods that you are interested in.  

Example

The example below demonstrates using the
TelnetListener class.

import com.jscape.inet.telnet.*;

public class MyTelnetListener implements TelnetListener {
   
   private Telnet telnet = null;
   
   public MyTelnetListener(Telnet telnet) {
      this.telnet = telnet;      
   }

   public void connected(TelnetConnectedEvent event) {
      System.out.println("Connected to host: "
 + event.getHost());
   }

   public void disconnected(TelnetDisconnectedEvent event) {
      System.out.println("Disconnected from host: "
 + event.getHost());
   }

   public void doOption(DoOptionEvent event) {
      // refuse all options

      telnet.sendWontOption(event.getOption());      
   }

   public void dontOption(DontOptionEvent event) {      

   }

   public void willOption(WillOptionEvent event) {
      // refuse all options

      telnet.sendDontOption(event.getOption());
   }

   public void wontOption(WontOptionEvent event) {      

   }

   public void doSubOption(DoSubOptionEvent event) {      

   }

   public void dataReceived(TelnetDataReceivedEvent event) {      
      // print data received to console

      System.out.print(event.getData());
   }
   
   public static void main(String[] args) {
      try {
         // create new telnet instance         

         Telnet telnet = new Telnet("hostname"
);
         
         // subscribe event listener

         telnet.addTelnetListener(new MyTelnetListener(telnet));
         
         // establish connection

         telnet.connect();
         
         // disconnect

         telnet.disconnect();
         
      } catch(Exception e) {
         e.printStackTrace();
      }
   }
}



Example


The example below demonstrates using the
TelnetAdapter class.

import com.jscape.inet.telnet.*;

public class MyTelnetAdapter extends TelnetAdapter {
   
   private Telnet telnet;
   
   public MyTelnetAdapter(Telnet telnet) {
      this.telnet = telnet;      
   }

   public void connected(TelnetConnectedEvent event) {
      System.out.println("Connected to host: "
 + event.getHost());
   }

   public void disconnected(TelnetDisconnectedEvent event) {
      System.out.println("Disconnected from host: "
 + event.getHost());
   }
   
   public void doOption(DoOptionEvent event) {
      // refuse all options

      telnet.sendWontOption(event.getOption());      
   }

   public void willOption(WillOptionEvent event) {
      // refuse all options

      telnet.sendDontOption(event.getOption());
   }

   
   public static void main(String[] args) {
      try {
         // create new telnet instance         

         Telnet telnet = new Telnet("hostname"
);
         
         // subscribe event listener

         telnet.addTelnetListener(new MyTelnetAdapter(telnet));
         
         // establish connection

         telnet.connect();
         
         // disconnect

         telnet.disconnect();
         
      } catch(Exception e) {
         e.printStackTrace();
      }
   }
}