Java – how to redirect to a jsp page from a servlet

javajspservlets

well
I have a jsp page with a login form, i'm using a servlet, if the username and password are correct the servlet redirects the user to another page else it redirects him to the login page again

when i log in with a correct username and password i'm redirected perfectly to reservation.jsp but when i put a wrong username or password in the form when i click on the submit button the page became blank

here is the servlet

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.*;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.mysql.jdbc.PreparedStatement;

/**
 * Servlet implementation class LogServlet
 */
@WebServlet("/LogServlet")
public class LogServlet extends HttpServlet {
private static final long serialVersionUID = 1L;




public LogServlet() {
    super();

}



protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub
    response.setContentType("text/html");


    String name=request.getParameter("name");
    String password=request.getParameter("password");

    PreparedStatement ps = null;
    ResultSet rs = null;

    try {
        Class.forName("com.mysql.jdbc.Driver");
        Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/log",
                "root","");
        ps = (PreparedStatement) conn.prepareStatement("select nom_client,username,password from client where username = ? and password = ?");

        ps.setString(1, name);
        ps.setString(2, password);
        rs=ps.executeQuery();



    try {
        while(rs.next()){
        if(password.equals(rs.getString("password")) && name.equals(rs.getString("username"))){

        HttpSession session=request.getSession();
        session.setAttribute("name",name);
        PrintWriter out=response.getWriter();
        request.getRequestDispatcher("reservation.jsp").include(request, response);
        }
        else{
            response.sendRedirect("/login.jsp");

        }}
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();

    }
    System.out.close();


    }
    catch(Exception e){e.printStackTrace();}


}
}

Best Solution

use request.getContextPath(), It will redirect you to login page.

response.sendRedirect(request.getContextPath()+"/login.jsp");

and if you are reaching to your login page in that case, pass request and response objects to your jsp page.

request.getRequestDispatcher(request.getContextPath()+"/login.jsp").forward(request,response);