TopComponent tc = WindowManager.getDefault().findTopComponent("Window2TopComponent");
Window2TopComponent window2TopComponent = (Window2TopComponent) tc;
window2TopComponent.jButton1.setText("hello");
TopComponent tc = WindowManager.getDefault().findTopComponent("Window2TopComponent");
Window2TopComponent window2TopComponent = (Window2TopComponent) tc;
window2TopComponent.jButton1.setText("hello");