Using filter filter to implement permission filtering problem

Package filter;

Import java.io.IOException;

Import Javax.servlet.Filter;
Import Javax.servlet.FilterChain;
Import Javax.servlet.FilterConfig;
Import javax.servlet.ServletException;
Import Javax.servlet.ServletRequest;
Import Javax.servlet.ServletResponse;
Import Javax.servlet.http.HttpServletRequest;
Import Javax.servlet.http.HttpServletResponse;
Import javax.servlet.http.HttpSession;

public class Adminfilter implements Filter {
public void init (Filterconfig filterconfig) throws Servletexception {
}
public void Dofilter (ServletRequest srequest, Servletresponse sresponse,
Filterchain Filterchain) throws Servletexception, IOException {
httpservletrequest request = (httpservletrequest) srequest;
HttpServletResponse response = (httpservletresponse) sresponse;
HttpSession session = Request.getsession ();
Boolean IsLogin = (Boolean) session.getattribute ("IsLogin");
if (islogin==null| | IsLogin = = False) {//If there is no content to jump back to the page directly
Response.sendredirect ("index.jsp");
} else {
Filterchain.dofilter (request, response);
}
}
public void Destroy () {
}

}

    <filter>
        <filter-name>adminfilter </filter-name>
        <filter-class>filter.adminfilter</ Filter-class>
    </filter>
    <filter-mapping>
         <filter-name>adminfilter</filter-name>
         <url-pattern> /services/* </url-pattern>
    </ Filter-mapping>