5

下面是我的代码；

    /*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package racms;

import java.io.IOException;
import javax.faces.application.NavigationHandler;
import javax.faces.context.FacesContext;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;


@WebFilter("/faces/*")
public class AuthenticationFilter implements Filter {

    @Override
    public void init(FilterConfig config) throws ServletException {
        // If you have any <init-param> in web.xml, then you could get them
        // here by config.getInitParameter("name") and assign it as field.
    }

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) res;
        HttpSession session = request.getSession(false);

        String pageRequested = request.getRequestURI().toString(); 
        //try{
        //FacesContext fctx = FacesContext.getCurrentInstance();
        //NavigationHandler myNav = fctx.getApplication().getNavigationHandler();



         if(session==null){       
               session = request.getSession(true); // will create a new session     
               response.sendRedirect("Login.xhtml");       
               //myNav.handleNavigation(fctx, null, "Login");
         }else if(session==null && pageRequested.contains("Login.xhtml")){       
                //  session.getAttribute("user");     
                chain.doFilter(request, response); // continue filtering       
         }else if((session.getAttribute("user")== null) && (!pageRequested.contains("Login.xhtml"))){          
             response.sendRedirect("Login.xhtml");
             //myNav.handleNavigation(fctx, null, "Login");
         }else {
             chain.doFilter(request, response);
         }
        //}catch(Exception e){
        //    System.out.println("Error :"+ e);
        //}
        /*if ((((HttpServletRequest) req).getSession().getAttribute("user") == null)) {
            FacesContext fctx = FacesContext.getCurrentInstance();
            NavigationHandler myNav = fctx.getApplication().getNavigationHandler();
            myNav.handleNavigation(fctx, null, "Login");
            //response.sendRedirect(request.getContextPath() + "/Login.xhtml"); // No logged-in user found, so redirect to login page.
        } else {
            chain.doFilter(req, res); // Logged-in user found, so just continue request.
        }*/
    }

    @Override
    public void destroy() {
        // If you have assigned any expensive resources as field of
        // this Filter class, then you could clean/close them here.
    }

}

如果我使用 FacesContext.getCurrentInstance()，会发生 java.lang.Nullpointer 异常；如果我使用 response.sendRedirect("Login.xhtml"); 它显示一个空白页面，如果我查看源代码，我可以在 jsf 中看到 Login.xhtml 的源代码。它不会呈现为 html..

我想要做的是：如果用户未登录并访问任何页面，则将他发送到 Login.xhtml，如果用户在 Login.xhtml 上，则向他显示要登录的页面。

请帮忙..

4

1 回答 1

12

重定向到与FacesServlet映射匹配的 URL。显然它被映射到/faces/*而不是*.xhtml. 然后重定向到faces/Login.xhtml.

这是一个重写，它简化了逻辑：

@Override
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
    HttpServletRequest request = (HttpServletRequest) req;
    HttpServletResponse response = (HttpServletResponse) res;
    HttpSession session = request.getSession(false);
    User user = (session != null) ? (User) session.getAttribute("user") : null;
    String loginURL = request.getContextPath() + "/faces/Login.xhtml"; 

    if (user == null && !request.getRequestURI().equals(loginURL)) {       
        response.sendRedirect(loginURL);
    } else {
        chain.doFilter(request, response);
    }
}
于 2012-06-22T03:28:33.953 回答