Question

public class LoginFilter implements Filter {
    @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);
        if (session == null ||
            session.getAttribute("currentSessionUser") == null) {
            response.sendRedirect("Loginpage.jsp"); // No logged-in user found, so redirect to login page.
            response.setHeader("Cache-Control",
                               "no-cache, no-store, must-revalidate"); // HTTP 1.1.
            response.setHeader("Pragma",
                               "no-cache"); // HTTP 1.0.                 response.setDateHeader("Expires", 0);
        } else {
            chain.doFilter(req,
                           res); // Logged-in user found, so just continue request.
        }
    }
}

我想在jsp中使用上面的代码强制用户在注销后重定向登录页面我们如何将其转换为jsp，以便我可以将其包含在我的jsp页面中。我在下面就像它一样，通过这样做，我们可以调用chain.filter()方法

<%@ page import=" java.io.IOException"%>
<%@ page import="javax.servlet.Filter"%>
<%@ page import="javax.servlet.FilterChain"%>
<%@ page import="javax.servlet.FilterConfig"%>
<%@ page import="javax.servlet.ServletException"%>
<%@ page import="javax.servlet.ServletRequest"%>
<%@ page import="javax.servlet.ServletResponse"%>
<%@ page import="javax.servlet.http.HttpServletRequest"%>
<%@ page import="javax.servlet.http.HttpServletResponse"%>
<%@ page import=" javax.servlet.http.HttpSession"%>
<%@ page import="javax.servlet.annotation.WebFilter"%>
<%
    //@Override         
    HttpServletRequest req = (HttpServletRequest) request;
    HttpServletResponse res = (HttpServletResponse) response;
    HttpSession session = req.getSession(false);
        if (session == null || session.getAttribute("userHash") == null)
        {  
        res.sendRedirect("/timescape/applicationservices/fileshare/vm/login/login.jsp"); // No logged-in user found, so redirect to login page.
        res.setHeader("Cache-Control", "no-cache, no-store, must-revalidate"); // HTTP 1.1. 
        res.setHeader("Pragma", "no-cache"); // HTTP 1.0.
        res.setDateHeader("Expires", 0);
        } 
        else
          {
          chain.doFilter(request, response); // Logged-in user found, so just continue request. 
          }

    %>

Answer 1

假设您只需要JSP中的重定向，您可以轻松地执行此操作：

<%
if (session == null || session.getAttribute("currentSessionUser") == null) {
    response.sendRedirect("Loginpage.jsp"); // No logged-in user found, so redirect to login page.                  
    response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate"); // HTTP 1.1.                 
    response.setHeader("Pragma", "no-cache"); // HTTP 1.0.
    response.setDateHeader("Expires", 0);
    return;
}
%>

这是有效的，因为在JSP中，总是有一个名为response的隐式变量包含HttpServletResponse对象，和总是有一个名为session的隐式变量包含HttpSession对象。

如何将以下代码段转换为JSP

1 个答案: