Java JSP сервлет 500 ошибка - PullRequest
Новая
       30

Java JSP сервлет 500 ошибка

0 голосов
/ 16 мая 2018

У меня есть веб-сайт на Java, который использует сервлет и JSP, а сервер - мой локальный хост.Большинство частей веб-сайта работают хорошо, но что-то не так, когда я нажимаю кнопку «Обновить пациента», отображается «500 внутренних» и появляется сообщение об ошибке: 

HTTP Status 500 – Internal Server Error

Type Exception Report

Message java.lang.NullPointerException

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception

org.apache.jasper.JasperException: java.lang.NullPointerException
    org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:565)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:481)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:386)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:330)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

java.lang.NullPointerException
    org.focus.DAO.PatientDAO.getAllPat(PatientDAO.java:220)
    org.focus.servlets.PatientUServlet.doGet(PatientUServlet.java:65)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    org.apache.jasper.runtime.PageContextImpl.doForward(PageContextImpl.java:742)
    org.apache.jasper.runtime.PageContextImpl.forward(PageContextImpl.java:712)
    org.apache.jsp.common.lp_jsp._jspService(lp_jsp.java:177)
    org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:443)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:386)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:330)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

А вот и моя «лу».jsp ": 

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ page import="java.util.*"%>

<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt"%>



<%
    String context = (String) request.getContextPath();
    String role = (String) session.getAttribute("role");
    String id = (String) session.getAttribute("id");
    String userName = (String) session.getAttribute("name");

    String errMsg = (String) request.getAttribute("error");
    if (errMsg == null) {
        errMsg = "";
    }

    String status = (String) request.getAttribute("status");
    if (status == null){
        status = "";
    }

%>


<html>
<head>


<script>
var context = '<%=context%>';
var role = '<%=role%>';
var id= '<%=id%>';
</script>
<!--import DHTMLX library component javascripts and css files-->
<link rel="stylesheet" type="text/css"
    href="<%=context%>/js/dhtmlx/dhtmlx.css" />

<link rel="stylesheet" type="text/css" href="<%=context%>/css/style.css">


</head>

<body>
<jsp:forward page="/PatientUServlet?action=listPatient"/>

</body>


<!--Footer-->
      <footer class="page-footer font-small blue pt-4 mt-4">


          <!--Copyright-->
          <div class="footer-copyright py-3 text-center">
              <div class="container-fluid">
                 <script>
var theDate=new Date();
document.write("© "+ theDate.getFullYear());</script>
              </div>
          </div>
          <!--/.Copyright-->

      </footer>
      <!--/.Footer-->
</html>

Вот мой" listPatient.jsp ": 

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>
<head>
  <%

  String  context = (String) request.getContextPath();
  String userName = (String) session.getAttribute("id");
  String role = (String) session.getAttribute("role");

    //out.println("CALLING main.jsp values: "+ userName +" "+role);
%>
   <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">


    <title>List Patient Template</title>

    <!-- Bootstrap core CSS -->
   <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/css/bootstrap.min.css" integrity="sha384-/Y6pD6FV/Vv2HJnA6t+vslU6fwYXjCFtcEpHbNJ0lyAFsXTsjBbfaDjzALeQsN6M" crossorigin="anonymous">


    <!-- Custom styles for this template -->
    <link href="jumbotron.css" rel="stylesheet">

<script>
    var context = '<%=context%>';   
</script>

<script>
function ConfirmDelete()
{
    var Delet_Confirm= confirm("Do you really want to delete this record ?");
 if (Delet_Confirm== true && <%=role%>=="ADMIN")
 {
   return true;
 }
 else
 {
  return false;
  }
}
</script>

</head>
<body>

<% if (role.equals("ADMIN")) {%>

<nav class="navbar navbar-expand-md navbar-dark fixed-top bg-dark">

      <a class="navbar-brand" href="#">Navbar</a>
      <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault" aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
      </button>

      <div class="collapse navbar-collapse" id="navbarsExampleDefault">

          <ul class="navbar-nav mr-auto">
          <li class="nav-item active">
            <a class="nav-link" href="<%=context%>/main.jsp">Home <span class="sr-only">(current)</span></a>
          </li>
          <li class="nav-item">
            <a class="nav-link" href="<%=context%>/common/myaccount.jsp">My Account</a>
          </li>


          <li class="nav-item">
            <a class="nav-link" href="<%=context%>/common/analysis.jsp?">Patient Analytics</a>
          </li>

  <li class="nav-item dropdown">
        <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
          Administrator Tasks
        </a>
        <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
          <a class="dropdown-item" href="<%=context%>/common/register.jsp">Register BHCO</a>
          <a class="dropdown-item" href="<%=context%>/common/addpatient.jsp">Add Patient</a>
          <a class="dropdown-item" href="<%=context%>/common/assignpatient.jsp">Assign Patient</a>
          <a class="dropdown-item" href="<%=context%>/common/lu.jsp">Update User</a>
          <a class="dropdown-item" href="<%=context%>/common/lp.jsp">Update Patient</a>
        </div>
      </li>

        </ul>

        <form class="form-inline my-2 my-lg-0" action="<%=context%>/LogoutServlet" method="post">
          <a class="form-control mr-sm-2" href="#">Your role:  <%=role%> </a> 
          <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Logout</button>

        </form>
       </div>   

    </nav>
<%}else{ %>

<nav class="navbar navbar-expand-md navbar-dark fixed-top bg-dark">

      <a class="navbar-brand" href="#">Navbar</a>
      <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault" aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
      </button>

      <div class="collapse navbar-collapse" id="navbarsExampleDefault">

          <ul class="navbar-nav mr-auto">
          <li class="nav-item active">
            <a class="nav-link" href="<%=context%>/main.jsp">Home <span class="sr-only">(current)</span></a>
          </li>
          <li class="nav-item">
            <a class="nav-link" href="<%=context%>/common/myaccount.jsp">My Account</a>
          </li>


          <li class="nav-item">
            <a class="nav-link" href="<%=context%>/common/analysis.jsp?">Patient Analytics</a>
          </li>



        </ul>

        <form class="form-inline my-2 my-lg-0" action="<%=context%>/LogoutServlet" method="post">
          <a class="form-control mr-sm-2" href="#">Your role:  <%=role%> </a> 
          <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Logout</button>

        </form>
       </div>   

    </nav>

<%} %>
<div class="box-centerside">
<br />
<br />
</div>

    <table class="table">
  <thead>
    <tr>
    <th>Patient Id</th>
    <th>First Name</th>
    <th>Last Name</th>
    <th>DOB</th>
    <th>Email</th>
    <th>Last Updated On</th>
    <th colspan=2>Action</th>
    </tr>
  </thead>
  <tbody>
      <c:forEach items="${pats}" var="pat">
                <tr>
                    <td><c:out value="${pat.patid}" /></td>
                    <td><c:out value="${pat.pfname}" /></td>
                    <td><c:out value="${pat.plname}" /></td>
                    <td><fmt:formatDate pattern="yyyy-MM-dd" value="${pat.dob}" /></td>
                    <td><c:out value="${pat.email}" /></td>
                    <td><c:out value="${pat.updatedate}" /></td>
                    <td><a href="<%=context%>/PatientUServlet?action=edit&patid=<c:out value="${pat.patid}"/>">Update</a></td>
                    <td><a onclick="return ConfirmDelete();" href="<%=context%>/PatientUServlet?action=delete&patid=<c:out value="${pat.patid}" />">Delete</a></td>
                </tr>
            </c:forEach>
        </tbody>
    </table>



<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.11.0/umd/popper.min.js" integrity="sha384-b/U6ypiBEHpOf/4+1nzFpr53nxSS+GLCkfwBdFNTxtclqqenISfwAzpKaMNFNmj4" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/js/bootstrap.min.js" integrity="sha384-h0AbiXch4ZDo7tp9hKZ4TsHbi047NrKGLO3SEJAg45jXxnGIfYzk4Si90RDIqNm1" crossorigin="anonymous"></script>
</body>
<!--Footer-->
      <footer class="page-footer font-small blue pt-4 mt-4">


          <!--Copyright-->
          <div class="footer-copyright py-3 text-center">
              <div class="container-fluid">
                 <script>
var theDate=new Date();
document.write("© "+ theDate.getFullYear() + " University of Pittsburgh");</script>
              </div>
          </div>
          <!--/.Copyright-->

      </footer>
      <!--/.Footer-->

Вот мой" PatientUServlet.java ": 

package org.focus.servlets;

import java.io.IOException;
import java.util.Date;
import java.text.ParseException;
import java.text.SimpleDateFormat;

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 org.focus.DAO.PatientDAO;
import org.focus.data.Patient;


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


        private static String INSERT_OR_EDIT = "/common/patient.jsp";
        private static String LIST_PAT = "/common/listPatient.jsp";
        private PatientDAO dao;


    /**
     * @throws Exception 
     * @see HttpServlet#HttpServlet()
     */
    public PatientUServlet() throws Exception {
        super();
        dao = new PatientDAO();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {



        String forward="";
        String action = request.getParameter("action");

        if (action.equalsIgnoreCase("delete")){
            int patid = Integer.parseInt(request.getParameter("patid"));
            dao.deletePat(patid);
            forward = LIST_PAT;
            request.setAttribute("pats", dao.getAllPat());    
        } else if (action.equalsIgnoreCase("edit")){
            forward = INSERT_OR_EDIT;
            int patid = Integer.parseInt(request.getParameter("patid"));
            Patient pat = dao.getPatById(patid);
            request.setAttribute("pat", pat);
        } else if (action.equalsIgnoreCase("listPatient")){
            forward = LIST_PAT;
            request.setAttribute("pats", dao.getAllPat());
        } else {
            forward = INSERT_OR_EDIT;
        }

        RequestDispatcher view = request.getRequestDispatcher(forward);
        view.forward(request, response);
                    }


    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
         Patient pat = new Patient();
         pat.setPatid(Integer.parseInt(request.getParameter("patid")));
         pat.setMed_no(Integer.parseInt(request.getParameter("medNo")));
         pat.setFamily_id(Integer.parseInt(request.getParameter("familyId")));
         pat.setBlock_id(Integer.parseInt(request.getParameter("blockId")));
         pat.setCommunity_id(Integer.parseInt(request.getParameter("communityId")));
         pat.setEmail(request.getParameter("email"));
         pat.setPfname(request.getParameter("firstName"));
         pat.setPmname(request.getParameter("midName"));
         pat.setPlname(request.getParameter("lastName"));
         pat.setPhone(request.getParameter("phone"));
         pat.setGender(request.getParameter("gender"));
         pat.setRace(request.getParameter("race"));
         pat.setMaritalstatus(request.getParameter("maritalstatus"));
         pat.setStreetnum(request.getParameter("streetNumber"));
         pat.setStreetname(request.getParameter("streetName"));
         pat.setAptno(request.getParameter("aptNo"));
         pat.setCity(request.getParameter("city"));
         pat.setState(request.getParameter("state"));
         pat.setZip(Integer.parseInt(request.getParameter("zip")));
         pat.setLatitude(Double.parseDouble(request.getParameter("latitude")));
         pat.setLongitude(Double.parseDouble(request.getParameter("longitude")));

        Date dob;
            try {
                dob = new SimpleDateFormat("yyyy-MM-dd").parse(request.getParameter("dob"));
                pat.setDob(dob);
            } catch (ParseException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();

            }

             dao.updatePat(pat);

             RequestDispatcher view = request.getRequestDispatcher(LIST_PAT);
             request.setAttribute("pats", dao.getAllPat());
             view.forward(request, response);
    }
   }

А вотмой "PatientDAO": 

 package org.focus.DAO;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import java.util.Date;

import org.apache.log4j.Logger;
import org.focus.data.PatientAssignDataBean;
import org.focus.data.PatientDataBean;
import org.focus.data.Patient;
import org.focus.db.JdbcUtil;
import org.focus.util.DbUtil;

public class PatientDAO {
    private static Logger log = Logger.getLogger(PatientDAO.class);


    private Connection connection1;

        public PatientDAO() throws Exception {

            connection1 = DbUtil.getConnection();
        }



        private static java.sql.Timestamp getCurrentTimeStamp() {

            java.util.Date today = new java.util.Date();
            return new java.sql.Timestamp(today.getTime());

        }

    public static ArrayList<PatientDataBean> getAllPatients(){
        ArrayList<PatientDataBean> result = new ArrayList<>();
        try ( Connection con = JdbcUtil.getConnection()) {
            String sql= "select patientid,patient_first_name,patient_last_name from patients";
            try (Statement st = con.createStatement()) {
                System.out.println(sql);
                ResultSet rs = st.executeQuery(sql);
                while (rs.next()){
                    result.add(new PatientDataBean(rs.getInt(1),rs.getString(2),rs.getString(3)));
                }
            } catch (Exception e) {
                log.error("Statement in patients search error", e);
                e.printStackTrace();
                result = null;
            }

            }
         catch (Exception e) {
            log.error("patients search error", e);
            e.printStackTrace();
            result = null;
        }

        return result;

    }
    public static ArrayList<PatientDataBean> getAllUnassignedPatients(){
        ArrayList<PatientDataBean> result = new ArrayList<>();
        try ( Connection con = JdbcUtil.getConnection()) {
            String sql= "select patientid,patient_first_name,patient_last_name "
                    + "from patients where patientid not in (select patientid from patientsassigns)";
            try (Statement st = con.createStatement()) {
                System.out.println(sql);
                ResultSet rs = st.executeQuery(sql);
                while (rs.next()){
                    result.add(new PatientDataBean(rs.getInt(1),rs.getString(2),rs.getString(3)));

                }
            } catch (Exception e) {
                log.error("Statement in patients search error", e);
                e.printStackTrace();
                result = null;
            }

            }
         catch (Exception e) {
            log.error("patients search error", e);
            e.printStackTrace();
            result = null;
        }

        return result;

    }

    public static ArrayList<PatientAssignDataBean> getAllAssignedPatientsAndUsers(){
        ArrayList<PatientAssignDataBean> result = new ArrayList<>();
        try ( Connection con = JdbcUtil.getConnection()) {
            String sql= "SELECT pa.uid,pa.patientid "
                    + "from patientsassigns pa";
            try (Statement st = con.createStatement()) {
                System.out.println(sql);
                ResultSet rs = st.executeQuery(sql);
                while (rs.next()){
                    result.add(new PatientAssignDataBean(rs.getString(1),rs. getInt(2)));
                }
            } catch (Exception e) {
                log.error("Statement in patientassign search error", e);
                e.printStackTrace();
                result = null;
            }

            }
         catch (Exception e) {
            log.error("patientassign search error", e);
            e.printStackTrace();
            result = null;
        }

        return result;

    }




    public static int getNameById(int pid){
        PatientDataBean result = new PatientDataBean();
        try ( Connection con = JdbcUtil.getConnection()) {
            String sql= "select patientid from patient where patientid = " + pid;
            try (Statement st = con.createStatement()) {
                System.out.println(sql);
                ResultSet rs = st.executeQuery(sql);
                while (rs.next()){
                    result = new PatientDataBean(rs.getInt(1));
                }
            } catch (Exception e) {
                log.error("Statement in users search error", e);
                e.printStackTrace();
                result = null;
            }

            }
         catch (Exception e) {
            log.error("patients search error", e);
            e.printStackTrace();
            result = null;
        }

        return result.getPatientId();

    }




    /*New CRUD OPERATIONS START FOR USERS - SM*/


//Join to patient assigns to get BHCO info to check if the BHCO is admin in order to delete
    public void deletePat(int pat) {
        try {
            PreparedStatement preparedStatement = connection1
                    .prepareStatement("delete from patients p where patientid=?");
            // Parameters start with 1
            preparedStatement.setInt(1, pat);
            preparedStatement.executeUpdate();

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


  //Join to patient assigns to get BHCO info to check if the BHCO is admin in order to update
    public void updatePat(Patient pat) {
        java.text.SimpleDateFormat sdf = 
                 new java.text.SimpleDateFormat("yyyy-MM-dd");

        String dob = sdf.format(pat.getDob());
        try {
            PreparedStatement preparedStatement = connection1
                    .prepareStatement("update patients p set med_no=?, family_id=?,block_id=?,community_id=?,email=?, "
                            +"patient_first_name=?,patient_mid_name=?, patient_last_name=?,patient_phone_number=?, "
                            +"gender=?,dob=?,race=?,maritalstatus=?,streetnumber=?,aptno=?,city=?,state=?,zip=?, "
                            +"latitude=?,longitude=?,update_date=? "
                            +"where patientid=?");
            // Parameters start with 1
            preparedStatement.setInt(1, pat.getMed_no());
            preparedStatement.setInt(2, pat.getFamily_id());
            preparedStatement.setInt(3, pat.getBlock_id());
            preparedStatement.setInt(4, pat.getCommunity_id());
            preparedStatement.setString(5, pat.getEmail());
            preparedStatement.setString(6, pat.getPfname());
            preparedStatement.setString(7, pat.getPmname());
            preparedStatement.setString(8, pat.getPlname());
            preparedStatement.setString(9, pat.getPhone());
            preparedStatement.setString(10, pat.getGender());
            //preparedStatement.setDate(11, new java.sql.Date(pat.getDob().getTime()));
            preparedStatement.setString(11, dob);
            preparedStatement.setString(12, pat.getRace());
            preparedStatement.setString(13, pat.getMaritalstatus());
            preparedStatement.setString(14, pat.getStreetnum());
            preparedStatement.setString(15, pat.getAptno());
            preparedStatement.setString(16, pat.getCity());
            preparedStatement.setString(17, pat.getState());
            preparedStatement.setInt(18, pat.getZip());
            preparedStatement.setDouble(19, pat.getLatitude());
            preparedStatement.setDouble(20, pat.getLongitude());
            preparedStatement.setTimestamp(21,getCurrentTimeStamp());
            preparedStatement.setInt(22, pat.getPatid());
            preparedStatement.executeUpdate();

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

    public List<Patient> getAllPat() {
        List<Patient> pats = new ArrayList<Patient>();
        try {
            Statement statement = connection1.createStatement();
            ResultSet rs = statement.executeQuery("select patientid,patient_first_name,patient_last_name,dob,email,update_date from patients");
            while (rs.next()) {
                Patient pat = new Patient();
                pat.setPatid(rs.getInt("patientid"));
                pat.setPfname(rs.getString("patient_first_name"));
                pat.setPlname(rs.getString("patient_last_name"));
                pat.setDob(rs.getDate("dob"));
                pat.setEmail(rs.getString("email"));
                pat.setUpdatedate(rs.getString("update_date"));
                pats.add(pat);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }

        return pats;
    }

    public Patient getPatById(int patid) {
        Patient pat = new Patient();
        try {
            PreparedStatement preparedStatement = connection1.
                    prepareStatement("select patientid,patient_first_name,patient_last_name,dob,email from patients where patientid=?");
            preparedStatement.setInt(1, patid);
            ResultSet rs = preparedStatement.executeQuery();

            if (rs.next()) {
                pat.setPatid(rs.getInt("patientid"));
                pat.setPfname(rs.getString("patient_first_name"));
                pat.setPlname(rs.getString("patient_last_name"));
                pat.setDob(rs.getDate("dob"));
                pat.setEmail(rs.getString("email"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }

        return pat;
    }





}

Я ожидаю, что я могу получить всех пациентов из базы данных, используя DAO, а затем, когда я нажимаю кнопку "Обновить пациента", он переходит к "lu.jsp"и в «lu.jsp» вы можете увидеть «listPatient.jsp», а затем распечатать информацию о каждом пациенте.Однако это не работает.А затем я набрал «lu.jsp» в своем браузере, он также показывает ту же «500 внутренняя ошибка».Затем я набрал "listPatient.jsp" в браузере, он не показывает ошибки, но на веб-странице нет информации о пациенте.Поэтому я думаю, что я не правильно оцениваю информацию о пациенте?что случилось?спасибо!

1 Ответ

0 голосов
/ 16 мая 2018

Вы получаете сообщение об ошибке нулевого указателя при использовании 

getAllpat()

Сначала проверьте его.

Другие возможности появления нулевого указателя. 

1. in Session creation or setAttribute() method.
2. in request parameter in servlet.
3. or in dao method if resultset have null value from database it will be not set in setmethod().

я ваместь третий тип ошибки, поэтому проверьте его в вашей базе данных или в вашем методе getallpat ()

...