如何使用会话将输入值从一个 jsp 页面访问到另一个 jsp 页面？

Question

In my login.jsp I used the following code.在我的 login.jsp 中，我使用了以下代码。 I created a session and intend to pass the username and email which the user will be inserting.我创建了一个会话并打算传递用户将插入的用户名和电子邮件。

<%
    try{
        Class.forName("com.mysql.jdbc.Driver");
        Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/db1","root","");
        Statement st=con.createStatement();
        %>
        hai
        <%
        String username=request.getParameter("username");
        String email=request.getParameter("email");
        String password=request.getParameter("password");
        ResultSet rs=st.executeQuery("Select * from user3");
        HttpSession sess = request.getSession(); 
        sess.setAttribute("username","username");
        sess.setAttribute("email","email");

        while(rs.next())
        {
            String username=rs.getString(1);
            String email1=rs.getString(2);
            String password1=rs.getString(3);

            if((email1.equals(email)) && (password1.equals(password)))
            {
                response.sendRedirect("book.html");
            }
            else
            {
                response.sendRedirect("register.html");
            }

        }

    }
    catch(Exception e)
{

}

%> %>

In another jsp page, I need to access these values ie the username and email so that I can insert it into a database.在另一个jsp 页面中，我需要访问这些值，即用户名和电子邮件，以便我可以将其插入到数据库中。

<body>


<%
HttpSession sess = request.getSession(false); 
String username=sess.getAttribute("username").toString();
String email=sess.getAttribute("email").toString();

try
{
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/db1", "root", "");
Statement st=conn.createStatement();

int i=st.executeUpdate("insert into busA(username,email)values('"+username+"','"+email+"')");
out.println("Data is successfully inserted!");
}
catch(Exception e)
{
System.out.print(e);
e.printStackTrace();
}
%>

These are my current code, but no values are being inserted into my database as I want it to.这些是我当前的代码，但没有按照我的意愿将值插入到我的数据库中。

Answer 1

In the first jsp you are setting the value for the session variables as strings instead of passing the username and password variables.在第一个 jsp 中，您将会话变量的值设置为字符串，而不是传递用户名和密码变量。

So instead of :所以而不是：

sess.setAttribute("username","username");
sess.setAttribute("email","email");

Try尝试

sess.setAttribute("username",username);
sess.setAttribute("email",email);

Also this issue may be relatied to not maintaning the session alive, default behavior for session in tomcat is using a cookie with the key JSESSIONID you can check with the browser dev tools if that cookie is being set and sent with the second jsp call此外，此问题可能与不保持会话处于活动状态有关，tomcat 中会话的默认行为是使用带有键 JSESSIONID 的 cookie，您可以使用浏览器开发工具检查该 cookie 是否正在设置并与第二个 jsp 调用一起发送

Inside the code you can use在您可以使用的代码中

request.getSession().getId()

To see if the session is the same between the 2 calls.查看两次调用之间的会话是否相同。

如何使用会话将输入值从一个 jsp 页面访问到另一个 jsp 页面？

问题描述

1 个解决方案

解决方案1
0 2019-11-24 18:41:11

如何使用会话将输入值从一个 jsp 页面访问到另一个 jsp 页面？

问题描述

1 个解决方案

解决方案1 0 2019-11-24 18:41:11

解决方案1
0 2019-11-24 18:41:11