Servlet Filter Filters

1. Encoding Conversion

     Public void DoFilter (servletrequest request, servletresponse response, Filterchain chain) throws IOException, Servletexception {        //  TODO auto-generated method stub        // Place Your code        here if (! charencoding.equals (request.getcharacterencoding ()))        {            request.setcharacterencoding (charencoding);        }                Response.setcharacterencoding (charencoding);                 // Pass the request along the filter chain         Chain.dofilter (request, response);    }

2. Permission Check Filter

 Public voidDoFilter (servletrequest request, servletresponse response, Filterchain chain) throws IOException, Servletexception {        //TODO auto-generated Method Stub//Place your code hereHttpServletRequest req=(httpservletrequest) request; HttpServletResponse Res=(httpservletresponse) response; String Servletpath=Req.getservletpath (); System. out. println ("Servletpath"+Servletpath); HttpSession Session=req.getsession (); String Flag= (String) Session.getattribute ("Flag"); if(Servletpath! =NULL&&(Servletpath.equals ("/21/login.jsp") ||(Servletpath.equals ("/21/index.jsp")) ||//servletpath.equals ("/21/hello.jsp") | |(Servletpath.equals ("/21/loginserverlet21"))) {chain.dofilter (request, response); }Else        {            if(Flag! =NULL&& Flag.equals ("login_success") {chain.dofilter (request, response); }            Else if(Flag! =NULL&& Flag.equals ("Login_error") {Req.setattribute ("msg","Login failed, please re-login!!!! <br/>"); Req.setattribute ("Return_uri", Servletpath); RequestDispatcher Rd= Req.getrequestdispatcher ("/21/login.jsp");            Rd.forward (req, res); }            Else{Req.setattribute ("msg","you haven't landed yet ."); Req.setattribute ("Return_uri", Servletpath); RequestDispatcher Rd= Req.getrequestdispatcher ("/21/login.jsp");            Rd.forward (req, res); }        }

3. Source code

Https://git.oschina.net/zkzk945/JavaEE.git

Servlet Filter Filters