Ex parte hearing

At the time and place appointed in and by the summons for any hearing of the information therein specified, any person having or claiming any estate or interest in the land may appear in the same manner as if the summons had been directed to him by name but if no such person nor the owner of the land appears then upon proof that the summons had been served in accordance with the provisions of this Act relating to service of summons, the information specified in the summons may be heard and adjudicated upon ex parte. 23