public class SpongeMove implements Listener{

	@EventHandler
	public void onMove(PlayerMoveEvent e){
	    Location from = e.getFrom();
	    Location to = e.getTo();
	    if ((from.getBlockX() != to.getBlockX()) || (from.getBlockY() != to.getBlockY()) || (from.getBlockZ() != to.getBlockZ())) {
	    	if(to.getBlock().getRelative(0, -1, 0).getType().equals(Material.SPONGE)){
	    		e.getPlayer().getInventory().addItem(new ItemStack(Material.DIAMOND, 1));
	    	}
	    }
	}
}