I am using the java displaytag library. I need to show the headers in the html page even if no-data is present. How can I enable it?
You need to change the value of the property basic.empty.showtable to true. You may do it on a specific table instance, by using the <display:setProperty> tag inside the <display:table> tag, or you may set it globally for the whole web application by setting it in your displaytag.properties file.
Read http://displaytag.sourceforge.net/1.2/configuration.html to understand how it works, discover the other useful properties.