First Two tables in the database.
1)In one table maintain two fields one is kno as primary key, and second field as List of Keywords in your site.
2)In the second table maintain three fields one for urlid, urls and kno (foreign key)
insert your urlid's as about.html,contactus.html
In the html page use the input tag.
<form action="search.jsp" method="post">
<input type="text" name="search">
<input type="submit" value="go">
then get the request in jsp page as follows
<% String search=request.getParameter("search");
Then in the jsp page write the query as
rs=st.executeQuery("select * from urls where urls.kno=(select kno from keywords where keyword='"+search+"')");