0

Hello Everyone,

I am trying to achieve pagination using jsp javascript and servlets.

Here is my code below:

SearchUserViews.java

`package TestPackage;

/**
 *
 * @author Sagar
 */

    private String _userid;
    private String _firstName;
    private String _lastName;
    private String _emailAddress;   

    public userProfile(){
        _userid = "";
        _firstName = "";
        _lastName = "";
        _emailAddress = "";      
    }
    public String getUserid() {
        return _userid;
    }
    public void setUserid(String userid) {
        this._userid = userid;
    }
    public String getFirstName() {
        return _firstName;
    }
    public void setFirstName(String firstName) {
        this._firstName = firstName;
    }   
    public String getLastName() {
        return _lastName;
    }
    public void setLastName(String lastName) {
        this._lastName = lastName;
    }
    public String getEmailAddress() {
        return _emailAddress;
    }
    public void setEmailAddress(String emailAddress) {
        this._emailAddress = emailAddress;
    } 
}

navigateDataGrid.java

package TestPackage;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class navigateDatagrid extends HttpServlet 
{

    public static void clearCookieUserManager(HttpServletRequest request, HttpServletResponse response) {

        Cookie[] collectionCookies = request.getCookies();

        for (Cookie c : collectionCookies) {

            if (c.getName().equalsIgnoreCase("FirstTimeAccessUserManager")) {

                c.setValue("");

                response.addCookie(c);

                break;
            }
        }
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException 
    {
        try
        {
        String buttonAction = request.getParameter("action");
        HttpSession session = request.getSession(false);
        int limitStart = 0;
        int limitMax = 10;
        int pageSize = 10;
        int allUserCount = 0;
        int pageIndex = 0; //start page from index 0
        session = request.getSession(false);
        if (session.getAttribute("limitStart") != null) {
            limitStart = Integer.parseInt(session.getAttribute("limitStart").toString());
        } else {
            session.setAttribute("limitStart", limitStart);
        }
        if (session.getAttribute("limitMax") != null) {
            limitMax = Integer.parseInt(session.getAttribute("limitMax").toString());
        } else {
            session.setAttribute("limitMax", limitMax);
        }
        if (session.getAttribute("pageIndex") != null) {
            pageIndex = Integer.parseInt(session.getAttribute("pageIndex").toString());
        } else {
            session.setAttribute("pageIndex", pageIndex);
        }
        if (session.getAttribute("pageSize") != null) {
            pageSize = Integer.parseInt(session.getAttribute("pageSize").toString());
        } else {
            session.setAttribute("pageSize", pageSize);
        }
        if (buttonAction.equalsIgnoreCase("Next")) {
            limitStart += pageSize;
            limitMax = pageSize;//max row return from query
            pageIndex += 1;           
        }else if(buttonAction.equalsIgnoreCase("Previous")){
            limitStart -= pageSize;
            limitMax = pageSize;//max row return from query
            pageIndex -= 1;
        }else{
            //reset all value to default
            limitStart  = 0;
            limitMax = 0;//max row return from query
            pageSize = Integer.parseInt(buttonAction);
            pageIndex = 0;
        }
        session.setAttribute("limitMax", limitMax);
        session.setAttribute("pageIndex", pageIndex);
        session.setAttribute("limitStart", limitStart);
        session.setAttribute("pageSize", pageSize);
        response.sendRedirect(request.getContextPath() + "/DataGrid.jsp");
    }

        catch(Exception e)

        {
            System.out.println(e);
        }
    }
}

userServices.java

package TestPackage;

/**
 *
 * @author Sagar
 */
import java.sql.Connection;
import java.sql.DriverManager;
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.logging.Logger;

public class userServices {
    public Connection getDbConn() {
        if(_dbConn == null){ 
           _dbConn = CheckConnection();
        }
        return _dbConn;
    }
    public void setDbConn(Connection aDbConn) {
        _dbConn = aDbConn;
    }
    public static String getDbUrl() {
        return _dbUrl;
    }
    public static void setDbUrl(String aDbUrl) {

        _dbUrl = aDbUrl;

    }  
    public static String getUser() {
        return _user;
    }
    public static void setUser(String aUser) {
        _user = aUser;
    }
    public static String getDbPassword() {
        return _dbPassword;
    }

    public static void setDbPassword(String aDbPassword) {
        _dbPassword = aDbPassword;
    }

    private List<userProfile> _collectionOfUserProfile;
    private static Connection _dbConn;
    private static String _dbUrl = "jdbc:oracle:thin:@localhost:1521:QUIZLIVE";
    private static String _user = "contestant";
    private static String _dbPassword = "Sagar_007";
    private final static Logger LOGGER = Logger.getLogger(userServices.class.getName());

    public userServices() {
        _collectionOfUserProfile = new ArrayList<>();
        _dbUrl = "jdbc:oracle:thin:@localhost:1521:QUIZLIVE";
        _user = "contestant";
        _dbPassword = "Sagar_007";      
    }
    public List<userProfile> getAllUsers(int limitStart, int limitMax) {
        ResultSet rs = null;

        String strsql = "select * from (select a.*, ROWNUM rnum from (select * from contestants order by user_id DESC) a where rownum <=" + Integer.toString(limitMax) + ") where rownum >=" + Integer.toString(limitStart) +"";
        //String strsql = "select * from (select a.*, ROWNUM rnum from (select * from contestants order by user_id DESC) a where rownum <=" + Integer.toString(limitMax) + ") where rownum >=" + Integer.toString(limitStart) +"";
        Connection conn = null;
        try {
            conn = CheckConnection();
            conn.setAutoCommit(true);
            PreparedStatement prepStatement = conn.prepareStatement(strsql);
            rs = prepStatement.executeQuery();

            while (rs.next()) {
                userProfile user = new userProfile();
                user.setUserid(rs.getString("user_id"));
                user.setFirstName(rs.getString("firstName"));
                user.setLastName(rs.getString("lastName"));
                user.setEmailAddress(rs.getString("emailAddress"));
                _collectionOfUserProfile.add(user);
            }

        } catch (SQLException ex) {
            //handle catch
            System.out.println(ex);
        } finally {
            closeConnection();
        }
        return _collectionOfUserProfile;

    }    

     public boolean deleteUser(String userid){
        boolean isSuccess = false;
        ResultSet rs = null;
        String strsql = "delete from contestant where UserID=?";
        PreparedStatement prepStatement = null;        
        Connection conn = null;
        try {
            conn = CheckConnection();
            conn.setAutoCommit(true);
            int rtnCode = 0;
            getDbConn().setAutoCommit(false);
            prepStatement = conn.prepareStatement(strsql);
            prepStatement.setString(1, userid);
            rtnCode = prepStatement.executeUpdate();
            if (rtnCode > 0) {
                _dbConn.commit();
                isSuccess  =true;
            }else{                
                _dbConn.rollback();
                isSuccess  = false;
            }     

        } catch (SQLException ex) {
           //catch handler
        } finally {
            closeConnection();
        }       

        return isSuccess;
    }
    public int countTableDataRow(String TableName) {
        TableName = "contestants";
        int ValCount = 0;
        Statement stmt = null;
        Connection conn = null;
        try {
            conn = CheckConnection();
            conn.setAutoCommit(true);
            String strsql = "SELECT Count(*) FROM Contestants "; //+ TableName;
            stmt = conn.createStatement();
            try (ResultSet rs = stmt.executeQuery(strsql)) 
            {
                rs.next();
                ValCount = rs.getInt(1);
            }
        } catch (SQLException se) {
            //handle catch
        } finally {
            closeConnection();
        }
        return ValCount;
    }
    public void closeConnection() {
        try {
            if (_dbConn != null) {
                _dbConn.close();
            }
        } catch (SQLException ex) {
            //handle catch
        }
    }
    public Connection CheckConnection() {
        try {
            Class.forName("oracle.jdbc.driver.OracleDriver");
        } catch (ClassNotFoundException e) {
            LOGGER.info(e.getMessage());                    
        }     

        Connection connection = null;
        try {
            connection = DriverManager.getConnection(_dbUrl, _user, _dbPassword);
        } catch (SQLException e) {
            LOGGER.info(e.getMessage());         
        }
        if (connection != null) {
            //LOGGER.info("You made it, take control your database now!");            

        } else {
            LOGGER.info("Failed to make connection!");    
        }
        return connection;
    }
    public List<userProfile> getCollectionOfUserProfile() {
        return _collectionOfUserProfile;
    }
    public void setCollectionOfUserProfile(List<userProfile> collectionOfUserProfile) {
        this._collectionOfUserProfile = collectionOfUserProfile;
    }
}

DataGrid.jsp

<%@page import="java.util.ArrayList"%>
<%@page import="java.util.List"%>
<%@page import="TestPackage.userProfile"%>
<%@page import="TestPackage.userServices"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>

<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
        <script type="text/javascript">

            function ConfirmOnDelete(item) {
              if (confirm("Are you sure to delete " + item + "?") === true)
                  return true;
              else
           return false;
           }
        </script>
    </head>
    <body>
        <h1>Data Grid In JSP</h1>




        <fieldset>
            <legend>Users Management</legend>
            ${errorMessage}
            ${successMessage}


            <div>
                <form action="<c:url value="/dataGridServlet" />" method="POST">
                      <%
                          int limitStart = 0;
                          int limitMax = 15;
                          int pageSize = 15;
                          int allUserCount = 0;
                          int pageIndex = 0; //start page from index 0
                          session = request.getSession(false);

                          //check cookie
                          Cookie[] collectionCookies = request.getCookies();
                          String cookieValue = "";
                          for (Cookie c : collectionCookies) {
                              if (c.getName().equalsIgnoreCase("FirstTimeAccessUserManager")) {
                                  if (c.getValue().equalsIgnoreCase("YES")) {
                                      c.setValue("NO");
                                      cookieValue = "NO";
                                  } else if (c.getValue().equalsIgnoreCase("")) {
                                      c.setValue("YES");
                                      session.removeAttribute("limitStart");
                                      session.removeAttribute("limitMax");
                                      session.removeAttribute("pageIndex");
                                      session.removeAttribute("pageSize");
                                  }
                              }
                          }
                          if (cookieValue.equalsIgnoreCase("")) {
                              Cookie cookie = new Cookie("FirstTimeAccessUserManager", "YES");
                              response.addCookie(cookie);
                          }

                          if (session.getAttribute("limitStart") != null) {
                              limitStart = Integer.parseInt(session.getAttribute("limitStart").toString());
                          } else {
                              session.setAttribute("limitStart", limitStart);
                          }

                          if (session.getAttribute("limitMax") != null) {
                              limitMax = Integer.parseInt(session.getAttribute("limitMax").toString());
                          } else {
                              session.setAttribute("limitMax", limitMax);
                          }

                          if (session.getAttribute("pageIndex") != null) {
                              pageIndex = Integer.parseInt(session.getAttribute("pageIndex").toString());
                          } else {
                              session.setAttribute("pageIndex", pageIndex);
                          }

                          if (session.getAttribute("pageSize") != null) {
                              pageSize = Integer.parseInt(session.getAttribute("pageSize").toString());
                          } else {
                              session.setAttribute("pageSize", pageSize);
                          }
 limitMax = pageSize;

                          userServices usersServ = new userServices();

                          List<userProfile> _collectionOfUserProfile = new ArrayList<userProfile>();                          


                          allUserCount = usersServ.countTableDataRow("usersprofile");

                          _collectionOfUserProfile = usersServ.getAllUsers(limitStart, limitMax);                         


                          String tableuser = "<table class=\"mainTable\" cellspacing=\"0\" rules=\"all\" id=\"MainContent_GridView1\" style=\"border-color:Gray;border-width:1px;border-style:Solid;width:95%;border-collapse:collapse;\">";
                          tableuser += "<tr style=\"color:White;background-color:#6699CC;font-weight:bold; padding:4px;\">";
                          tableuser += "<th scope=\"col\">No.</th>";
                          tableuser += "<th scope=\"col\">User ID</th>";
                          tableuser += "<th scope=\"col\">First Name</th>";
                          tableuser += "<th scope=\"col\">Last Name</th>";
                          tableuser += "<th scope=\"col\">Email</th>";
                          tableuser += "<th scope=\"col\"> </th>";
                          tableuser += "<th scope=\"col\"> </th></tr>";

                          int numberRecord = pageIndex * pageSize;
                          int balance = allUserCount - numberRecord;
                          int startRekodToShow = numberRecord + 1;
                          int index = startRekodToShow;
                          for (userProfile u : _collectionOfUserProfile) {
                              tableuser += "<tr style=\"border-color:Gray;border-width:1px;border-style:Solid;\">";
                              tableuser += "<td style=\"border-color:#CCCCCC;border-width:1px;border-style:Solid;width:20px;padding:4px;\">";
                              tableuser += Integer.toString(index);
                              tableuser += "</td>";
                              tableuser += "<td style=\"border-color:#CCCCCC;border-width:1px;border-style:Solid;width:100px;padding:4px;\">";
                              tableuser += u.getUserid();
                              tableuser += "</td>";
                              tableuser += "<td style=\"border-color:#CCCCCC;border-width:1px;border-style:Solid;width:80px;padding:4px;\">";
                              tableuser += u.getFirstName();
                              tableuser += "</td>";
                              tableuser += "<td style=\"border-color:#CCCCCC;border-width:1px;border-style:Solid;width:80px;padding:4px;\">";
                              tableuser += u.getLastName();
                              tableuser += "</td>";
                              tableuser += "<td style=\"border-color:#CCCCCC;border-width:1px;border-style:Solid;width:80px;padding:4px;\">";
                              tableuser += u.getEmailAddress();
                              tableuser += "</td>";
                              tableuser += "<td style=\"border-color:#CCCCCC;border-width:1px;border-style:Solid;width:50px;padding:4px;\">";
                              tableuser += "<input type=\"submit\" class=\"buttonLikeLink\" name=\"" + u.getUserid() + "\" onclick=\"return ConfirmOnDelete('" + u.getUserid() + "');\" value=\"Remove\" />";
                              tableuser += "</td>";
                              tableuser += "<td style=\"border-color:#CCCCCC;border-width:1px;border-style:Solid;width:50px;padding:4px;\">";
                              tableuser += "<input type=\"submit\" class=\"buttonLikeLink\" name=\"" + u.getUserid() + "\" value=\"Modify\" ></input>";
                              tableuser += "</td>";
                              tableuser += "</tr>";
                              index++;
                          }
                          tableuser += "</table>";
                          out.print(tableuser);
                      %>
            </form>

           <!-- Create logic next and previous in this section -->
            <%
                if (allUserCount > pageSize) {
                    String form = "";
                    if (pageIndex > 0) {
                        //form += "<h1>Page " + Integer.toString(pageIndex) + "</h1>";
                    }
                    form += "<form action=\"" + request.getContextPath() + "/navigateDatagrid\" method=\"POST\" >";
                    if (limitStart > 0) {
                        if (balance > pageSize) {
                            if ((pageSize + numberRecord) == allUserCount) {
                                //do not show next
                            } else {
                                //show next
                                form += "<input type=\"submit\" class=\"buttonNav\" id=\"bNext\" name=\"action\" value=\"Next\" />";
                            }
                        } else {
                            if ((balance + numberRecord) == allUserCount) {
                                //do not show next
                            } else {
                                //show next
                                form += "<input type=\"submit\" class=\"buttonNav\" id=\"bNext\" name=\"action\" value=\"Next\" />";
                            }
                        }
                       if (startRekodToShow != 1) {
                            form += "<input type=\"submit\" class=\"buttonNav\" id=\"bPrevious\" name=\"action\" value=\"Previous\" />";
                        }
                    } else {
                        form += "<input type=\"submit\" class=\"buttonNav\" id=\"bNext\" name=\"action\" value=\"Next\" />";
                    }
                    form += "</form>";
                    out.print(form);
                }
            %>
        </div>




        <%
            if (allUserCount > 15) {
                String grid_row_controller = "<div id=\"MainContent_PanelDropDownGVPage\" style=\"display:inline;\">";
                grid_row_controller += "Total Users Per Page :";
                grid_row_controller += "<form method=\"POST\" action=\"" + request.getContextPath() + "/navigateDatagrid\" id=\"pageRowform\" >";
                grid_row_controller += "<select name=\"action\" style=\"width:50px;\" onchange=\"document.forms['pageRowform'].submit()\">";

                if (pageSize == 10) {
                    grid_row_controller += "<option value=\"10\" selected=\"selected\">10</option>";
                } else {
                    grid_row_controller += "<option value=\"10\">10</option>";
                }

                if (pageSize == 15) {
                    grid_row_controller += "<option selected=\"selected\" value=\"15\">15</option>";
                } else {
                    grid_row_controller += "<option value=\"15\">15</option>";
                }

                if (pageSize == 25) {
                    grid_row_controller += "<option selected=\"selected\" value=\"25\">25</option>";
                } else {
                    grid_row_controller += "<option value=\"25\">25</option>";
                }
                if (pageSize == 35) {
                    grid_row_controller += "<option selected=\"selected\" value=\"35\">35</option>";
                } else {
                    grid_row_controller += "<option value=\"35\">35</option>";
                }
                if (pageSize == 50) {
                    grid_row_controller += "<option selected=\"selected\" value=\"50\">50</option>";
                } else {
                    grid_row_controller += "<option value=\"50\">50</option>";
                }

                grid_row_controller += "</select>";
                grid_row_controller += "</form>";
                out.print(grid_row_controller);
            }
        %>        


        Show         
        <%

            if (allUserCount > pageSize) {
                if (pageIndex == 0) {
                    out.print("1 - " + pageSize);
                } else {
                    if (balance > pageSize) {
                        out.print(startRekodToShow + " - " + (pageSize + numberRecord));
                    } else {
                        out.print(startRekodToShow + " - " + (balance + numberRecord));
                    }
                }
            } else if (allUserCount == 0) {
                out.print("0");
            } else {
                out.print("1 - " + allUserCount);
            }
        %>      
        Record(s)  From 
        <%
            out.print(allUserCount);
        %>
        User(s)


    </fieldset>
</body>
</html>

The issue being faced is when i access the DataGrid.jsp, the first page is able to show the data correctly however when i click next nothing shows. I am able to filter up to 25 records and all, but i cannot be able to view the next data when clicking next.

P.S I am using oracle database as the backend.

All help much appreciated.

Edited by peter_budo: Code formatting, splitting files

2
Contributors
3
Replies
18
Views
3 Years
Discussion Span
Last Post by stultuske
1

honestly, I stopped going over your code when I saw two major flaws in it.
first one: I saw this

catch (SQLException se) {
            //handle catch
        }

at least two times. if you don't understand why that is bad, don't write 'complex' applications before you understand the reason why.

secondly: remove the scriplets from your .jsp file.
the jsp file is the GUI, there shouldn't be any logic in it. all the logic should be handled by the servlets.

Votes + Comments
Empty catch, no point to go further
0

hy stultuske,

the places where the //handle catch has been commented are methods that delete the record from the table. Plus if you dont recommend to use scriptlets request if you can kindly share a tutorial which can be a better way to code and achive the pagination functionality rather than the approach I have used.

0

any book that teaches about servlets is better than the approach you used.
using scriplets is bad design.
catch blocks should always at the very least log what is going wrong.

you post 'code', but not the actual code you are running. if it is your actual code, it won't even compile. re-check the code you've shown for SearchUserViews.java and try and see if you can guess how I know it won't compile.

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