java - How to manipulate jsp hyperlinks in doGet method inside a Servlet? -

i'm new in java world. trying develop acme demo using simple csv file database validate user names , passwords. wonder if possible make hyperlinks on index.jsp page, take other jsp pages of same website if click them. far know hyperlinks invoke doget method inside servle, -in case- gonna redirected secure jsp if credentials valid of course. has worked 1 hyperlink , make things more dynamic no matter how many links there??!!

jsp

 <a href ="<%=request.getcontextpath()%>/loginnow.do"> content1</a>   <!-- here add more links --> 

servlet

    @override   protected void doget(httpservletrequest request, httpservletresponse response)     throws servletexception, ioexception   {     processrequest(request, response);      //response.sendredirect("login.jsp");       httpsession session= request.getsession(true);      if ((session.getattribute("usersession") != null) && (session.getattribute("usersession").equals(session.getid())))     {       response.sendredirect("content1.jsp");       // how can doget method manage multiple links here?      }     else     {       response.sendredirect("login.jsp");     }   } 

you should use servlet filter.

a filter component invoked requests given url-mapping, and/or requests given servlet.

the filter can check if user logged in. if he's loged in, asks container proceed, i.e. invoke target servlet if there no filter. if he's not logged in, filter can return error, or redirect login page, or whatever wants.

see http://www.oracle.com/technetwork/java/filters-137243.html introduction , examples of servlet filters.