Start Plugin

I have followed Openfire development guide to make my plugin.

Here is my build.xml :

<plugin> 
    <class>org.jivesoftware.openfire.plugin.Limitator</class>
     <name>Limitator</name> 
     ..... 
</plugin> 

Here is my plugin :

package org.jivesoftware.openfire.plugin;
 
public class Limitator implements Plugin {  
     private InterceptorManager interceptorManager;  
     private IQRouter iqRouter;  
     private IQPacketInterceptor myPacketInterceptor; 
     private IQHandler handler;  
 
     public Limitator() {  
        interceptorManager = InterceptorManager.getInstance(); 
        iqRouter = XMPPServer.getInstance().getIQRouter(); 
        myPacketInterceptor = new IQPacketInterceptor(); 
        handler = new FilterIQHandler("FilterIQHandler"); 
 
        RightToFile("Start"); 
    }  
 
     public void initializePlugin(PluginManager manager, File pluginDirectory) { 
         interceptorManager.addInterceptor(myPacketInterceptor); 
         //iqRouter.addHandler(handler); 
     }  
 
     public void destroyPlugin() { 
       interceptorManager.removeInterceptor(myPacketInterceptor); 
       //iqRouter.removeHandler(handler); 
     }  
 
     private void RightToFile(String message){ 
        Writer writer = null;  
        try { 
             writer = new BufferedWriter(new OutputStreamWriter( new FileOutputStream("D:\\filename.txt"), "utf-8")); 
             writer.write(message + "   "); 
             writer.write(System.getProperty( "line.separator" ));
         } catch (IOException ex) { // report }  
        finally { try {writer.close();} catch (Exception ex) {} } 
     } 
} 

There is no new file created after file upload. (this means plugin not started) What did I wrong? Thanks.