I`m new to jsp (java server pages). Can anyone give an ideea how to
create a serch engine in jsp, to look through a database and output
the result.

first what about your knowledge about the architecture of Search
Engine? you must know how to how to create the crawler then take the
result from it and store in the database and then retrieve the result
from database
then make the ranking algorithm on these result
so you can make it as java application or applet then it is ease to
make it by JSP and Servlet

Java Search Engine is a server-side search engine program for web sites. Search engines provide to the site visitors easy and fast way to find what they want on your site. If you want to have search engine on your site - .
Java Search Engine has common Java API interfaces such as JSP, servlets and EJB. Can save results as XML and transform them into HTML using XSLT stylesheets.