How to clear the system clipboard in Java? -

how can clear system clipboard in java? have tried

toolkit.getdefaulttoolkit().getsystemclipboard().setcontents(null, null); 

but had thrown npe:

exception in thread "awt-eventqueue-0" java.lang.nullpointerexception: contents     @ sun.awt.datatransfer.sunclipboard.setcontents(sunclipboard.java:98) 

you can create special transferable explicitly contains no data, detailed in blog post:

  clipboard.setcontents(new transferable() {     public dataflavor[] gettransferdataflavors() {       return new dataflavor[0];     }      public boolean isdataflavorsupported(dataflavor flavor) {       return false;     }      public object gettransferdata(dataflavor flavor) throws unsupportedflavorexception {       throw new unsupportedflavorexception(flavor);     }