Wicket saves jsessionid (actually tomcat does that) , now can I make those jsessionid cookies as persistent cookies and can I use them to make the user login next time he/she visits my page .
The idea behind 'JSESSIONID' cookie is to track a live user session. Once this session is expired at the server side, i.e. inside Tomcat, the cookie becomes useless. The browser will send it to the web server and there it will be ignored.
What you ask for is "RememberMe" cookie. This cookie usually brings encrypted information about the user. If the user session is expired then the application will forward you to the login page. During this process the application may check for such RememberMe cookie and use it to auto-login this user without asking for her credentials.
Apache Wicket provides DefaultAuthenticationStrategy with support for RememberMe cookie. See wicket-auth-roles SingInPanel.java and the source code for http://examples6x.wicket.apache.org/authentication3 to see how it works. You could also use Spring Security, Apache Shiro, Stormpath, etc. for the same functionality if you decide so!