I have a JButton created using the following code.
JButton button = new JButton ( "Document",appletRec.getIcon()) ;
button.addActionListener ( this ) ;
button.setOpaque ( true ) ; //changed false from true.
button.setFocusPainted ( true ) ; //changed false from true.
button.actAsLink ( true ) ;
button.setHighlightForeground ( Color.blue ) ;
button.setVerticalTextPosition ( SwingConstants.BOTTOM ) ;
button.setVerticalAlignment ( SwingConstants.TOP ) ;
button.setHorizontalTextPosition ( SwingConstants.CENTER ) ;
But my button is appearing like this

I want to move the text to the bottom of the button. Any suggestion highly appreciated.
button.setVerticalAlignment(SwingConstants.BOTTOM) will move everything (text + icon) to the bottom of the button.
If you want spacing between the text and the icon, you can use
button.setIconTextGap(int distance)