获取浏览器的url

Question

我试图在一些servlet和jsp之间添加一个过滤器，以便在显示jsp之前登录的用户。问题是，我试图检索浏览器的网址，这是转发到登录页面，但我找不到如何。我尝试在过滤器中获取URI，并将其作为请求的属性发送给Connexion servlet，但是，它不起作用。

package com.forum.filters;

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 RestrictionFilter implements Filter {
    public static final String CONNEXION = "/WEB-INF/connexion.jsp";
    public static final String ATT_USER = "utilisateur";
    public static final String CHEMIN = "chemin";

    public void destroy() {

    }

    public void doFilter(ServletRequest req, ServletResponse res,
            FilterChain chain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) res;

        String chemin = request.getRequestURI().substring(
                request.getContextPath().length());

        HttpSession session = request.getSession();

        if (session.getAttribute(ATT_USER) == null) {
            request.setAttribute(CHEMIN, chemin);
            request.getRequestDispatcher(CONNEXION).forward(request, response);
        } else {
            chain.doFilter(request, response);
        }
    }

    public void init(FilterConfig fConfig) throws ServletException {

    }

}

package com.forum.servlets;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.forum.beans.Utilisateur;
import com.forum.form.ConnexionForm;

public class Connexion extends HttpServlet {
    public static final String ATT_USER = "utilisateur";
    public static final String ATT_FORM = "form";
    public static final String VUE = "/WEB-INF/connexion.jsp";

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        this.getServletContext().getRequestDispatcher(VUE)
                .forward(request, response);
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        ConnexionForm form = new ConnexionForm();
        String chemin = (String) request.getAttribute("chemin");

        Utilisateur utilisateur = form.connecterUtilisateur(request);

        HttpSession session = request.getSession();

        if (form.getErreurs().isEmpty()) {
            session.setAttribute(ATT_USER, utilisateur);
            if (chemin == null || chemin.startsWith("/connexion"))
                response.sendRedirect("/projetForum/forum");
            else
                response.sendRedirect("/projetForum" + chemin);
        } else {
            request.setAttribute(ATT_USER, null);
            request.setAttribute(ATT_FORM, form);
            this.getServletContext().getRequestDispatcher(VUE)
                    .forward(request, response);
        }
    }
}

 <servlet>
 <servlet-name>Connexion</servlet-name>
 <servlet-class>com.forum.servlets.Connexion</servlet-class>
 </servlet>
 <servlet-mapping>
 <servlet-name>Connexion</servlet-name>
 <url-pattern>/connexion</url-pattern>
</servlet-mapping>
<filter>
     <filter-name>RestrictionFilter</filter-name>
     <filter-class>com.forum.filters.RestrictionFilter</filter-class>
</filter>
<filter-mapping>
     <filter-name>RestrictionFilter</filter-name>
     <servlet-name>Nouveau</servlet-name>
     <servlet-name>Profil</servlet-name>
     <servlet-name>Editer</servlet-name>
     <servlet-name>Repondre</servlet-name>
</filter-mapping>

Answer 1

从筛选器中可以看出，在将referrer URL分派到登录页面之前，您已经使用request.setattribute（CHEMIN,CHEMIN）；存储了该URL。在本例中，在登录jsp上（我假设是/WEB-INF/connexion.jsp)，您可以将其作为表单隐藏字段插入：

<form ...>
  <input type="hidden" name="referrer" value="<%= request.getAttribute("chemin") %>"/>
   ...
</form>

当表单提交时，您可以通过“referrer”请求参数检索referrer URL