Java netbeans glassfish空指针服务器错误

当我们运行代码并尝试登录时，我们不断得到以下信息： 服务器错误500: “java.lang.nullpointerexception”

我们试图将HTML文本字段的内容传递到一个函数中，该函数在db中搜索电子邮件和密码，并返回一个用户类

如果该用户类具有“admin”类型，则登录时应将其带到admin页面，但实际情况并非如此

所有NullPointException似乎都链接到将电子邮件和密码传递给用户管理器，但是我测试了设置特定值，使db与变量电子邮件和密码匹配，但是我仍然收到相同的错误

非常感谢你的帮助

glassfish服务器的输出堆栈：

---

由于找不到数据库，因此出现了大量SQL错误。潜在的问题可能是：

package Servlet;

import Manager.UserManager;
import Model.User;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import utils.IConstants;
import utils.StringUtils;

public class LoginServlet extends HttpServlet {

    /**
     * Processes requests for both HTTP <code>GET</code> and         <code>POST</code>
 * methods.
 *
 * @param request servlet request
 * @param response servlet response
 * @throws ServletException if a servlet-specific error occurs
 * @throws IOException if an I/O error occurs
 */
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {String email = request.getParameter("email");
    String password = request.getParameter("password");

    if (StringUtils.isStringEmpty(email) || StringUtils.isStringEmpty(password)) {

        RequestDispatcher rd = request.getRequestDispatcher("/index.html");
        rd.forward(request, response);

    } else {

        UserManager uMgr = new UserManager();
        User user = uMgr.loginUser(email, password);
        if (user == null) {
            RequestDispatcher rd = request.getRequestDispatcher("/index.html");
            rd.forward(request, response);
        } else {
            request.getSession(true).setAttribute(IConstants.SESSION_KEY_USER, user);
            if (user.getUsertype().equals(IConstants.USER_TYPE_ADMIN)) {
                RequestDispatcher rd = request.getRequestDispatcher("/adminHome.jsp");
                rd.forward(request, response);
            } else if (user.getUsertype().equals(IConstants.USER_TYPE_GENERAL_USER)) {
                RequestDispatcher rd = request.getRequestDispatcher("/genUserHome.jsp");
                rd.forward(request, response);
            } else {
                RequestDispatcher rd = request.getRequestDispatcher("/index.html");
                rd.forward(request, response);
            }
        }
    }

}

// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
 * Handles the HTTP <code>GET</code> method.
 *
 * @param request servlet request
 * @param response servlet response
 * @throws ServletException if a servlet-specific error occurs
 * @throws IOException if an I/O error occurs
 */
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    processRequest(request, response);
}

/**
 * Handles the HTTP <code>POST</code> method.
 *
 * @param request servlet request
 * @param response servlet response
 * @throws ServletException if a servlet-specific error occurs
 * @throws IOException if an I/O error occurs
 */
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    processRequest(request, response);
}

/**
 * Returns a short description of the servlet.
 *
 * @return a String containing servlet description
 */
@Override
public String getServletInfo() {
    return "Short description";
}// </editor-fold>

}

---

这会阻止数据库的创建。

嘿，谢谢你的帮助，我最初发布了错误的输出，来自上一次迭代。这是我们当前的输出。提前感谢（新的pastebin链接）

UserManager.java

第34行发生的事情的可能重复？如果您可以将

loginUser（）

方法也添加到问题中，这会有所帮助。

java.io.FileNotFoundException: C:\Users\112419442\Desktop\BootStrapLogin\sql\createdb.txt