Java 使用准备好的语句登录Servlet

Java 使用准备好的语句登录Servlet,java,servlets,Java,Servlets,我试图找出以下代码中的错误: public void service(HttpServletRequest request, HttpServletResponse response){ try{ user1 = request.getParameter("nameLog"); pass1 = request.getParameter("passLog"); String userid = null;

我试图找出以下代码中的错误:

public void service(HttpServletRequest request, HttpServletResponse response){
        try{
            user1 = request.getParameter("nameLog");
            pass1 = request.getParameter("passLog");
            String userid = null;
            String passdb = null;
            String query = "select user, pass from login where `user` = ? and `pass`=?";

            PreparedStatement pst = conn.prepareStatement(query);
            ResultSet rs = pst.executeQuery();
            pst.setString(1, user1);
            pst.setString(2, pass1);

            while(rs.next()){
                userid = rs.getString("user1");
                passdb = rs.getString("pass1");

                pst.executeQuery();
            }
            if(userid.equals(user1)&& passdb.equals(pass1)){
                response.sendRedirect("/WebContent/login/Main.html");

            }


        }catch(Exception ex){
        ex.printStackTrace();
        }
    }
我尝试登录到我的应用程序数据库列名为user和pass,但出现错误:

java.sql.SQLException: No value specified for parameter 1
在这一排

ResultSet rs = pst.executeQuery();
如何消除此错误并登录到我的页面


谢谢

订购事宜!在调用executeQuery之前,需要传递参数,如下所示:

PreparedStatement pst = conn.prepareStatement(query);            
pst.setString(1, user1);
pst.setString(2, pass1);            
ResultSet rs = pst.executeQuery();

秩序很重要!在调用executeQuery之前,需要传递参数,如下所示:

PreparedStatement pst = conn.prepareStatement(query);            
pst.setString(1, user1);
pst.setString(2, pass1);            
ResultSet rs = pst.executeQuery();

您正在设置值之前执行查询。应该是:

PreparedStatement pst = conn.prepareStatement(query);
pst.setString(1, user1);
pst.setString(2, pass1);

ResultSet rs = pst.executeQuery();

您正在设置值之前执行查询。应该是:

PreparedStatement pst = conn.prepareStatement(query);
pst.setString(1, user1);
pst.setString(2, pass1);

ResultSet rs = pst.executeQuery();

我们的差距只有一秒,而我的差距只有一秒,还没投票给你们;我们的差距只有一秒,而我的差距只有一秒,还没投票给你们;