Monitoriar el Clipboard

import java.awt.datatransfer.Transferable;
/*
 
 @author L-EYER
 @see GlassFish Tools Bundle For EclipseVersion: 0.9.9
   
*/
public class ThreadClipboard extends Thread{
	public static void main(String[] args){
		new ThreadClipboard();
	}
	public ThreadClipboard(){this.start();}
	private boolean _run = true;
	private String string;
	private Transferable transferable;
    private final String getClipboard()
    {
    transferable =
    	java.awt.Toolkit.getDefaultToolkit().getSystemClipboard().getContents(null);
	        try {
	            if (transferable != null && 
	            		transferable.isDataFlavorSupported(
	            				java.awt.datatransfer.DataFlavor.stringFlavor)) {
	                string =
	                	(String)transferable.getTransferData(
	                			java.awt.datatransfer.DataFlavor.stringFlavor);
	                return string;
	            }
	        } catch ( java.awt.datatransfer.UnsupportedFlavorException exception) 
	        {System.err.println(exception);_run = false;System.exit(0);
	        } catch (java.io.IOException e)
	        {System.err.println(e);System.out.println("GClipboard.getClipboard()");
	        _run = false;System.exit(0);
	        }
	        return null;
	    }
	public String getText() {return string;}
	public void setText(String text) {this.string = text;}
	public boolean is_run() {return _run;}
	public void set_run(boolean _run) {this._run = _run;
	}
	private int DELAY = 50;
	@Override public synchronized void run()
	{
	while(is_run()){
	try {
		String stringClipboard = getClipboard();
		if(stringClipboard!= null){
			System.out.println(stringClipboard);
			    }
		else{continue;
		    }
		Thread.sleep(DELAY);
	   } catch (InterruptedException e) {
		System.err.println(e);System.exit(0);
	   }		
	 }
   }
}