Question

这是我的Java代码和HTML代码。

当用户点击“重定向”按钮时，我想将他重定向到登录页面并终止当前会话。我已成功完成重定向部分，但我不知道如何终止会话。我想在HTML中的action =中使用session.invalidate。可以这样做吗？如果没有，那么最好的选择是什么？ THX。

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.WebServlet;
import java.io.*;

@WebServlet("/test1")
public class test1 extends HttpServlet{

public void init(){

        System.out.println("init is called");
    }

    public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,IOException{

        res.setContentType("text/html");

        PrintWriter pw=res.getWriter();// used to type in the browser

        String s=req.getParameter("username");
        String s2=req.getParameter("pwd");

        // Create a session object if it is already not  created.
          HttpSession session = req.getSession(true);



        if(s.equals("ace")&& s2.equals("123"))
        {
            //pw.println("<h1>"+"Welcome to the world of servlets "+s+"</h1>");



            String title= "Welcome to the world of servlets: "+s;

            String s3="The session id is: "+session.getId();

            String docType =
                      "<!doctype html public \"-//w3c//dtd html 4.0 " +
                      "transitional//en\">\n";

                pw.println(docType +
                                "<html>\n" +
                                "<head><title>" + title + "</title></head>\n" +
                                "<body bgcolor=\"#f0f0f0\">\n" +
                                "<h1 align=\"center\">" + title + "</h1>\n" +
                                "<h1 align=\"center\">" + s3 + "</h1>\n"+
                                "<ul>\n" +
                                "<input type=\"button\" onclick=\"location.href('http://localhost:8080/AkshayServlet2/test.html');\" value=\"Redirect\">"+ 

                                "</ul>\n" +
                                "</body></html>");

                session.invalidate();

                //System.out.println.print("You have logged out");


        }
        else
        {

            pw.println("Please enter the correct username and password");
            req.getRequestDispatcher("test.html").include(req, res);;

        } 


    }

    public void destroy(){

        System.out.println("calling destroy method");

    }

}

HTML code：

<html>
<body> 

<form action="test1" method=get>  <!-- we use xy because we used xy in the url in web.xml. We have to map it to the url -->

Enter UserName: <input type=text name=username><br>
Enter Password: <input type=password name=pwd><br>

<input type=submit value="Login">

</form>  

</body>

</html>

Answer 1

您必须调用HttpServletRequest :: getSession方法，以便创建新会话以替换先前无效的会话。

在会话失效行之后添加以下代码：

req.getSession(true);

点击“重定向”按钮，终止我的会话并重定向到登录页面

1 个答案: