为什么不能用datatables来添加在数据库中查到的数据

 String datastr="{ "data":[";

datastr = datastr + "{"stuNumber":""+stuNumber+"","

                        + ""stuName":""+stuName+"","

                        + ""stuNamed":""+stuNamed+"","

                        + ""stuSex":""+stuSex+"","

                        + ""stuNation":""+stuNation+"","

                        + ""stuBirth":""+stuBirth+"","

                        + ""stuNative":""+stuNative+"","

                        + ""stuRegious":""+stuRegious+"","

                        + ""stuPolitical":""+stuPolitical+"","

                        + ""stuHealth":""+stuHealth+"","

                        + ""stuSpecial":""+stuSpecial+"","

                        + ""stuResidence":""+stuResidence+"","

                        + ""stuSchoolRoll":""+stuSchoolRoll+"","

                        + ""regiousSeat":""+regiousSeat+"","

                        + ""stuID":""+stuID+"","

                        + ""stuAddress":""+stuAddress+"","

                        + ""stuMobile":""+stuMobile+"","

                        + ""stuEmail":""+stuEmail+"","

                        + ""stuEntranceWay":""+stuEntranceWay+"","

                        + ""stuAlone":""+stuAlone+"","

                        + ""stuMartyr":""+stuMartyr+"","

                        + ""stuSingle":""+stuSingle+"","

                        + ""stuFarmer":""+stuFarmer+"","

                        + ""stuEnteranceDate":""+stuEnteranceDate+"","

                        + ""stuClass":""+stuClass+""},";

                }

                 datastr=datastr.substring(0,datastr.length()-1);

                datastr=datastr+"]}";

The JQuery-datatables alert errors all time.

this is the servlet:



    package servlet;



    import bean.Student;

    import dao.StudentDAO;

   

    import javax.servlet.ServletException;

    import javax.servlet.http.HttpServlet;

    import javax.servlet.http.HttpServletRequest;

    import javax.servlet.http.HttpServletResponse;

    import java.io.IOException;

    import java.io.PrintWriter;

    import java.sql.ResultSet;

    import java.sql.SQLException;

   

    /**

     *

     *

     */

    public class GetStuInfoServlet extends HttpServlet {

        private String stuNumber;

        private String stuName;

        private String stuNamed;

        private String stuSex;

        private String stuNation;

        private String stuBirth;

        private String stuNative;

        private String stuRegious;

        private String stuPolitical;

        private String stuHealth;

        private String stuSpecial;

        private String stuResidence;

        private String stuSchoolRoll;

        private String regiousSeat;

        private String stuID;

        private String stuAddress;

        private String stuMobile;

        private String stuEmail;

        private String stuEntranceWay;

        private String stuAlone;

        private String stuMartyr;

        private String stuSingle;

        private String stuFarmer;

        private String stuEnteranceDate;

        private String stuClass;

   

        String datastr="{ "data":[";//ajax  json

   

        public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException,IOException{

            request.setCharacterEncoding("utf-8");

            response.setCharacterEncoding("utf-8");

            response.setContentType("application/json; charset=utf-8");

            String classNumbers = null;

            String stuNumbers = null;

            ResultSet resultSet = null;

            classNumbers = request.getParameter("classNumber");



            StudentDAO studentDAO = new StudentDAO();

            Student student = null;

            PrintWriter out = response.getWriter();

            out.flush();

            try {

                resultSet = studentDAO.getStudentByClassNumber(classNumbers);

            } catch (Exception e) {

                e.printStackTrace();

            }

                resultSet = studentDAO.getStudentByStuNumber(stuNumber);

               resultSet = studentDAO.getStudentByClassNumber(classNumbers);

   

            try {

                while (resultSet != null & resultSet.next()){

                    this.stuNumber = resultSet.getString("stu_number");

                    this.stuName = resultSet.getString("stu_name");

                    this.stuNamed = resultSet.getString("stu_named");

                    this.stuSex = resultSet.getString("stu_sex");

                    this.stuNation = resultSet.getString("stu_nation");

                    this.stuBirth = resultSet.getString("stu_birth");

                    this.stuNative = resultSet.getString("stu_native");

                    this.stuRegious = resultSet.getString("stu_religious");

                    this.stuPolitical = resultSet.getString("stu_political");

                    this.stuHealth = resultSet.getString("stu_health");

                    this.stuSpecial = resultSet.getString("stu_special");

                    this.stuResidence = resultSet.getString("stu_residence");

                    this.stuSchoolRoll = resultSet.getString("stu_school_roll");

                    this.regiousSeat = resultSet.getString("regious_seat");

                    this.stuID = resultSet.getString("stu_id");

                    this.stuAddress = resultSet.getString("stu_adress");

                    this.stuMobile = resultSet.getString("stu_mobile");

                    this.stuEmail = resultSet.getString("stu_email");

                    this.stuEntranceWay = resultSet.getString("stu_entrance_way");

                    this.stuAlOne= resultSet.getString("stu_alone");

                    this.stuMartyr = resultSet.getString("stu_martyr");

                    this.stuSingle = resultSet.getString("stu_single");

                    this.stuFarmer = resultSet.getString("stu_farmer");

                    this.stuEnteranceDate = resultSet.getString("stu_enterance_date");

                    this.stuClass = resultSet.getString("stu_class");

   

                    if (stuNumber==null){stuNumber="";}

                    if (stuName==null){stuName="";}

                    if (stuNamed==null){stuNamed="";}

                    if (stuSex==null){stuSex="";}

                    if (stuNation==null){stuNation="";}

                    if (stuBirth==null){stuBirth="";}

                    if (stuNative==null){stuNative="";}

                    if (stuRegious==null){stuRegious="";}

                    if (stuPolitical==null){stuPolitical="";}

                    if (stuHealth==null){stuHealth="";}

                    if (stuSpecial==null){stuSpecial="";}

                    if (stuResidence==null){stuResidence="";}

                    if (stuSchoolRoll==null){stuSchoolRoll="";}

                    if (regiousSeat==null){regiousSeat="";}

                    if (stuID ==null){stuID ="";}

                    if (stuAddress==null){stuAddress="";}

                    if (stuMobile==null){stuMobile="";}

                    if (stuEmail==null){stuEmail="";}

                    if (stuEntranceWay==null){stuEntranceWay="";}

                    if (stuAlOne==null){stuAlOne="";}

                    if (stuMartyr==null){stuMartyr="";}

                    if (stuSingle==null){stuSingle="";}

                    if (stuFarmer==null){stuFarmer="";}

                    if (stuEnteranceDate==null){stuEnteranceDate="";}

                    if (stuClass==null){stuClass="";}

   

   

                    datastr = datastr + "{"stuNumber":""+stuNumber+"","

                        + ""stuName":""+stuName+"","

                        + ""stuNamed":""+stuNamed+"","

                        + ""stuSex":""+stuSex+"","

                        + ""stuNation":""+stuNation+"","

                        + ""stuBirth":""+stuBirth+"","

                        + ""stuNative":""+stuNative+"","

                        + ""stuRegious":""+stuRegious+"","

                        + ""stuPolitical":""+stuPolitical+"","

                        + ""stuHealth":""+stuHealth+"","

                        + ""stuSpecial":""+stuSpecial+"","

                        + ""stuResidence":""+stuResidence+"","

                        + ""stuSchoolRoll":""+stuSchoolRoll+"","

                        + ""regiousSeat":""+regiousSeat+"","

                        + ""stuID":""+stuID+"","

                        + ""stuAddress":""+stuAddress+"","

                        + ""stuMobile":""+stuMobile+"","

                        + ""stuEmail":""+stuEmail+"","

                        + ""stuEntranceWay":""+stuEntranceWay+"","

                        + ""stuAlone":""+stuAlone+"","

                        + ""stuMartyr":""+stuMartyr+"","

                        + ""stuSingle":""+stuSingle+"","

                        + ""stuFarmer":""+stuFarmer+"","

                        + ""stuEnteranceDate":""+stuEnteranceDate+"","

                        + ""stuClass":""+stuClass+""},";

                }

            } catch (SQLException e) {

                e.printStackTrace();

            }finally {

                datastr=datastr.substring(0,datastr.length()-1);

                datastr=datastr+"]}";

            }

            out.flush();

            out.write(datastr);

            out.close();

   

   

   

        }

   

        public void doGet(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException{

            this.doPost(request,response);

        }

    }



And the studentDAO:



        package dao;

    import bean.Student;

    import java.sql.Connection;

    import java.sql.DriverManager;

    import java.sql.PreparedStatement;

    import java.sql.ResultSet;

   

    /**

     * Created by Emitor on 16-12-7.

     */

    public class StudentDAO {

        private Connection conn ;

        private Student student = null;

   

        public void initConnection() throws Exception {

            Class.forName("com.mysql.jdbc.Driver");

            cOnn= DriverManager.getConnection("jdbc:mysql://localhost:3306/mysystem","yupei","yupei");

        }

        public void closeConnection() throws Exception {

            conn.close();

        }

   

        public ResultSet getStudentByClassNumber(String classNumber)throws Exception{

            initConnection();

            String sql = "SELECT * FROM stu_info WHERE stu_class = ?";

            PreparedStatement ps = conn.prepareStatement(sql);

            ps.setString(1,classNumber);

            ResultSet resultSet = ps.executeQuery();

            ps.close();

            closeConnection();

            return resultSet;

        }

        public ResultSet getStudentByStuNumber(String stuNumber)throws Exception{

            initConnection();

            String sql = "SELECT * FROM stu_info WHERE stu_number = ?";

            PreparedStatement ps = conn.prepareStatement(sql);

            ps.setString(1,stuNumber);

            ResultSet resultSet = ps.executeQuery();

            ps.close();

            closeConnection();

            return resultSet;

        }

    }



I try to use firebug to find the problem, it seems like not the right Json response. But I am really a new guy in Json. so I feel so confused now. Anyone help me to find the bug, please. Thanks a lot in advance.

This is the jsp:



        <%@ page cOntentType="text/html;charset=UTF-8" language="java" %>