为我的Web应用程序编写授权过滤器（JSF 2.0）

Question

遵循一些建议，我决定为自己的Web应用程序编写自己的授权过滤器（我没有使用容器管理的安全性，因此我必须采用这种方式）。

这是我的第一个过滤器，因此我对如何实现它感到有些困惑。这是我到目前为止所做的：

package 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;

import entities.Role;

public class RestrictPageFilter implements Filter {

    FilterConfig fc;

    public void init(FilterConfig filterConfig) throws ServletException {
        // The easiest way to initialize the filter
        fc = filterConfig;
    }

    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {

        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse resp = (HttpServletResponse) response;
        HttpSession session = req.getSession(true);
        String pageRequested = req.getRequestURL().toString();

        Role currentUser = (Role) session.getAttribute("userRole");

        //Pages that are allowed with no need to login:
        //-faq.xhtml
        //-index.jsp
        //-login.xhtml
        //-main.xhtml
        //-registration.xhtml

        //NOW pages that are restricted depending on the type of user
        //buyoffer.xhtml(Only BUYER)
        //sellerpanel.xhtml(Only SELLER)
        //adminpanel.xhtml(Only ADMINISTRATOR)

        //HOW SHOULD I IMPLEMENT THAT??
        if(currentUser != null && currentUser.getType().equals("BUYER")) {

        }
        if(currentUser != null && currentUser.getType().equals("SELLER")) {

        }
        if(currentUser != null && currentUser.getType().equals("ADMINISTRATOR")) {

        }


    }

    public void destroy() {
        // Not needed
    }
}

如您所见，我在那里留下了评论。有人可以帮我整理一下此过滤器，也可以给我一些伪代码提示，我应该如何完成呢？

我在网上看到了一些示例，但是没有一个示例根据用户类型进行不同的过滤。

不胜感激您的帮助:)

更新资料

我创建了一个xml文件来帮助进行过滤（它位于WEB-INF / classes内部）

<access>
    <buyer>
        <page>buyoffer.xhtml</page>
        <page>faq.xhtml</page>
        <page>index.jsp</page>
        <page>login.xhtml</page>
        <page>main.xhtml</page>
        <page>registrationSucceded.xhtml</page>     
    </buyer>
    <seller>
        <page>sellerpanel.xhtml</page>
        <page>faq.xhtml</page>
        <page>index.jsp</page>
        <page>login.xhtml</page>
        <page>main.xhtml</page>
        <page>registrationSucceded.xhtml</page>     
    </seller>
    <administrator>
        <page>sellerpanel.xhtml</page>
        <page>faq.xhtml</page>
        <page>index.jsp</page>
        <page>login.xhtml</page>
        <page>main.xhtml</page>
        <page>registrationSucceded.xhtml</page>     
    </administrator>
</access>

<!-- THE REGISTRATION PAGES SHOULD NOT BE ACCESSIBLE IF THE USER IS LOGGED IN -->

我从init（）方法读取文件。

public class RestrictPageFilter implements Filter {

    private FilterConfig fc;
private InputStream in;

    public void init(FilterConfig filterConfig) throws ServletException {
        // The easiest way to initialize the filter
        fc = filterConfig;
        //Get the file that contains the allowed pages
        in = this.getClass().getResourceAsStream("/allowedpages.xml");
    }

    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {

        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse resp = (HttpServletResponse) response;
        HttpSession session = req.getSession(true);
        String pageRequested = req.getRequestURL().toString();

        //Get the value of the current logged user 
        Role currentUser = (Role) session.getAttribute("userRole");
        if (currentUser != null) {

        }
    }

    public void destroy() {
        // Not needed
    }
}

Answer 1

如果您需要允许访问，只需致电

// it will process request normally, means it will leave the control from Filter
chain.doFilter(request, response);

如果您想限制用户，请致电

//take some action
response.sendRedirect("URL to some page");//it will simply make user redirected

一些建议

• 使用某种XML属性文件使其可配置，您的代码对我而言似乎很难，明天可能会添加另一个页面，因此您需要重新编译您的Filter。

• 如果允许，那么只需使用Spring Security，它就会具有不错的功能。你也不会发明轮子