Web Filters (Jsp+cookie+filter-free tomcat) use records __JS

Note: The filter mainly filters the value inside the request,response.

*web.xml----

* Login Action Add cookie-------

*filter Filter Gets cookies------

(without a new username, password, read the cookie directly through the query database, get user user,

Request.getsession (). setattribute ("user", User1))

* Other action inside get---------

(Duser user= (Duser) request.getsession (). getattribute ("user"),//) Automatic logon

* Logoff: Deleting cookies----------

1, Web configuration file--Filter all requests

<filter>
  <filter-name>LoginFilter</filter-name>
  <filter-class> com.djh.listener.loginfilter</filter-class>
 </filter>
 <filter-mapping>
  < filter-name>loginfilter</filter-name>
  <url-pattern>/*</url-pattern>
 </ Filter-mapping>

2. Add Cookies to login action

Session.setattribute ("user", user);
      Cookie cookie1 = new Cookie ("username", User.getuphonenum ());  
               Cookie cookie2 = new Cookie ("Password", User.getupassword ());               Cookie cookie3 = new Cookie ("SESSIONID", "----");
               
               Cookie1.setmaxage (*);  
               Cookie2.setmaxage (*);               cookie3.setmaxage (0); 
               
               
               Cookie1.setpath ("/");  
               Cookie2.setpath ("/");               Cookie3.setpath ("/");  
                 
               Response.addcookie (cookie1);  
               Response.addcookie (COOKIE2);  

3, Filter class loginfilter--Main method is Dofilter, in this method to remove request.getccookies () value, set to Request.getsession (). setattribute ("User", User1);
, the other interface takes the "user" value from the filter set to remove the Uname,password automatic login.

Package Com.djh.listener;

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.Cookie;
Import Javax.servlet.http.HttpServletRequest;

Import Javax.servlet.http.HttpServletResponse;
Import Org.springframework.context.ApplicationContext;

Import Org.springframework.context.support.ClassPathXmlApplicationContext;
Import Com.djh.entity.DUser;
Import Com.djh.service.LoginService;

Import com.djh.util.MD5; /** * @author Shenpai * Filter for automatic user login/public class Loginfilter implements filter {ApplicationContext context = new 
 Classpathxmlapplicationcontext (New string[]{"Applicationcontext-*.xml"}); Loginservice loginservice= (Loginservice) Context.getbean ("Loginservice");//Get UserService instance of the bean with public void Destroy () {} public void Dofilter (ServletRequest req, servletresPonse resp, Filterchain chain) throws IOException, Servletexception {try {//System.out.println ("------------
   ----"); Convert ServletRequest and Servletresponse to HttpServletRequest and HttpServletResponse types HttpServletRequest request= (
   HttpServletRequest) req;
   HttpServletResponse response = (httpservletresponse) resp; First check that the user is logged on to Duser user= (duser) request.getsession (). getattribute ("user");/if (user!=null) {Chain.dofilter (req
    Uest, response);
   Return
   //Check to see if the user brought a cookie String username= null;
   String password =null;
   Cookie[] Cookies=request.getcookies (); for (int i=0;cookies!=null && i<cookies.length;i++) {//System.out.println (Cookies[i].getname () +cookies[i
             ].getvalue () + "----filter to obtain cookies---");  
             if (Cookies[i].getname (). Equals ("username")) {username = Cookies[i].getvalue (); } if (Cookies[i].getname (). Equals ("password")) {password = Cookies[i].getvalue();  
              } if (Username==null | | password==null) {//user did not bring Cookie Chain.dofilter (req, resp);  
         Return  
         }//The user brought the cookie duser user1 = Loginservice.finduserbyphonenumandpassword (username, password);  
         String Save_password = User1.getupassword ();  
             if (!password.equals (Save_password)) {Chain.dofilter (req, resp);  
         Return  } request.getsession (). setattribute ("user", User1);
         Through the requsest to the relevant need to login information in the action, the action inside through the reqest. Obtain user information and implement automatic login.
         Chain.dofilter (req, resp); 
  Return
  catch (Exception e) {e.printstacktrace ();




 } public void init (Filterconfig arg0) throws servletexception {}}

4, action to obtain user information, to achieve automatic login.

Duser user= (Duser) session.getattribute ("user");//Get the Login user Object

5. Logout: Delete Cookies

User logoff public
 String logout () {
            HttpSession session = Request.getsession (false);
            if (session!= null)
            session.removeattribute ("user");
            Cookie cookie = Cookieutils.<span style= "Background-color: #3333ff" >delCookie</span> (request);
            if (cookie!= null)
                    Response.addcookie (cookie);
            return "Login";
 

Private Cookieutils cookieutils = new Cookieutils ();

Delete Cookie public
 cookie <span style= "color: #3333ff;" >delCookie</span> (HttpServletRequest request) {
         cookie[] cookies = request.getcookies ();
         if (cookies!= null) {for
                  (Cookie cookie:cookies) {
                         if ("username". Equals (Cookie.getname ())) {
                                Cookie.setv Alue ("");
                                Cookie.setmaxage (0);
                          } else if ("Password". Equals (Cookie.getname ())) {
                                cookie.setvalue ("");
                                Cookie.setmaxage (0);
                         }
                         return cookie;
                 }
         return null;
 }