Как сбросить значение с помощью сеансов или файлов cookie в веб-приложении, которое использует Java и JSP? - PullRequest
Новая
       23

Как сбросить значение с помощью сеансов или файлов cookie в веб-приложении, которое использует Java и JSP?

0 голосов
/ 11 марта 2020

Я пытался использовать Sessions, Cookies, Cache et c, но значение продолжает увеличиваться с каждым вызовом базы данных - см. ProfileServlet. java (соответствующая переменная с именем 'Counted' установлена ​​в качестве атрибута сеанса ниже, и значение переменной извлекается из базы данных с использованием DBViewSchedules. java class) 

//@MultipartConfig
@WebServlet("/ProfileServlet")
public class ProfileServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

     String scheduler;
     String storedSched;

    //Schedule   
        String chooseDate;          
        String selectTask;
        String selectTask2;         
        String schedDate;
        int taskNum;
        String timeFrom;
        String timeTo;
        String name;
        String notes;


        String[] DBdate2;
        String[] DBtimeFrom2;
        String[] DBtimeTo2;
        String[] DBname2;
        String[] DBnotes2;
        String[] DBstatus2;

        String addTask;
        String saveSched;

        HttpSession session;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public ProfileServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

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

        selectTask = request.getParameter("selectTask");

        if(selectTask != null)
        {   
            session = request.getSession();
            try {               
                chooseDate = request.getParameter("chooseDate");

                //DBViewSchedules
                DBViewSchedules callMethod = DBViewSchedules.getValues(chooseDate);

                session.setAttribute("Counted", callMethod.counted);

                //Cookie cookie = new Cookie("Counted", String.valueOf(callMethod.counted));                
                //cookie.setMaxAge(0);
                //cookie.setMaxAge(-1);
                //response.addCookie(cookie);
                //cookie.setValue("0"); 

                request.setAttribute("DBdate2", callMethod.storeDate); 
                request.setAttribute("DBtimeFrom2", callMethod.storeTFrom);
                request.setAttribute("DBtimeTo2", callMethod.storeTTo);
                request.setAttribute("DBname2", callMethod.storeName);
                request.setAttribute("DBnotes2", callMethod.storeNotes);
                request.setAttribute("DBstatus2", callMethod.storeStatus);

                response.setHeader("Pragma", "no-cache");
                response.setHeader("Cache-Control", "no-store");
                response.setHeader("Expires", "0");
                response.setDateHeader("Expires",-1);

                request.getRequestDispatcher("SchedulerWithData.jsp").forward(request, response); 
                session.invalidate();

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

        }

    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }


}

Планировщик. jsp файл - обратите внимание, что ссылка на 'Countted' указана в функции addRow () (т. е. var number = "$ {Counted}"). Функция 'addRow ()' вызывается в методе 'onload' тега body этой страницы. Ссылка на функцию addData () указана в теге кнопки с id = "selectTask" ниже. 

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
    <%@ taglib uri = "http://java.sun.com/jsp/jstl/core" prefix = "c" %>



<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
 <META HTTP-EQUIV="Pragma" CONTENT="no-cache">
    <META HTTP-EQUIV="Expires" CONTENT="-1">
<title>Insert title here</title>
<link rel="StyleSheet" href="Images/StyleSheet.css">
</head>
<body onload = "addRow()">

<%
   //clear cache
    response.setHeader("Expires", "0");
    response.setHeader("Cache-Control","no-cache, no-store, must-revalidate");
    response.addHeader("Cache-Control", "post-check=0, pre-check=0");
    response.setHeader("Pragma", "no-cache");

    //cookies
    Cookie cookies[] = request.getCookies();    
    String str = null;    
    for(Cookie c : cookies)
    {

        if(c.getName().equals("Counted"))
        {
            c.setMaxAge(0);

            c.setValue("0");
            str = c.getValue();
            System.out.println(" ");
            System.out.println("Cookie(Counted1) from Scheduler = " +Integer.valueOf(str));     
            System.out.println(" ");


        }
        else
        {
            System.out.println(" ");
            System.out.println("No Cookie from Scheduler.");
            System.out.println(" ");

        }
    }

  //session
    //if(session.getAttribute("Counted")==null)
    //{
    //response.sendRedirect("Main.jsp");    
    //}
    //System.out.println("Session number from Scheduler:  " +session.getAttribute("Counted"));

%>

<h1 style="text-align: center; padding-top: 50px; font-size: 50px;">Scheduler</h1>
<section class = "section1">
<form action="ProfileServlet" class="container4" enctype="multipart/form-data" id = "formTest">

    <label class="lbl2" style="text-align: center;">Search for an existing schedule:</label><br><br>
    <input type="date" name="chooseDate" id = "chooseDate"></input> 
    <button type="submit" class="btn7" name="selectTask" id="selectTask" onClick = "addData()">Search</button><br><br> 

</form>
</section>

<section class = "section1">
<form action="ProfileServlet" class="container4">

        <label class="lbl2" style="float:middle;";>Create a new Schedule:&nbsp</label><br><br>
        <!--<input type="date" name="date2" id = "date2" style="float:left;"></input> 
        <button type="submit" class="btn6" name="select" id="select">Search</button><br> -->        
        <button type="submit" class="btn3" name="save" id="save">Save</button><br>


<table name="table1" id="table1"><br>
 <thead>    
   <tr> 
     <th>   
        <label class="lbl2"></label>
    </th> 
    <!--<th>    
        <label class="lbl2">Task#</label>
    </th>-->
        <th>    
        <label class="lbl2">Date</label>
    </th>
    <th colspan = "2">  
        <label class="lbl2">Time</label>
    </th>
    <th>    
        <label class="lbl2">Task</label>
    </th>
    <th>
        <label class="lbl2">Notes</label>
    </th>
    <th>
        <label class="lbl2">Status</label><br>
    </th>
   </tr>
</thead>
<tbody>
  <tr>
    <td>
         <input type="checkbox" name="checkTask" id = "checkTask">                       
    </td>
    <!--<td style = "padding-left: 15px;">           
         <textarea  name="taskNum" id = "taskNum" rows="1" cols="2">${DBtaskNum}</textarea>      
    </td>-->
    <td>
    <input type="date" name="date" id = "date" style="float:left;" required = "true" value="${DBdate}"></input>
    </td>
    <td>        
        <input type="time" name="from" id = "from" required = "true" value="${DBtimeFrom}"></input>     
    </td>
     <td>           
        <input type="time" name="to" id = "to" required = "true" value="${DBtimeTo}"></input>   
    </td>
    <td>
        <textarea  name="taskName" id = "taskName" rows="2" cols="25" value= "In Progress" required = "true" >${DBname}</textarea>  
    </td>
    <td>
        <textarea name="notes" id = "notes"rows="2" cols="25">${DBnotes}</textarea>
    </td>
    <td>
        <select name="status" id="status" value = "${DBstatus}">
                    <OPTION value="Scheduled" name="scheduled" id="scheduled" ${DBstatus == 'Scheduled' ? 'selected': ''}>Scheduled</OPTION>
                    <OPTION value="In-Progress" name="in-Prog" id="in-Prog" ${DBstatus == 'In-Progress' ? 'selected' : ''}>In-Progress</OPTION>
                    <OPTION value="Complete" name="complete" id="complete" ${DBstatus == 'Complete' ? 'selected' : ''}>Complete</OPTION>
                </select>
    </td>

   </tr>

 </tbody>
</table>
</form>
</section>

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

var number = "${Counted}";
var expires = "expires=Thu, 01 Jan 1977 00:00:00 UTC";    
var rIndex, table = document.getElementById("table1");


function addData(){ 
      if(window.XMLHttpRequest) { 
        var xhttp = new XMLHttpRequest();
        xhttp.onreadystatechange=function() {
            if (xhttp.readyState == 4 && xhttp.status == 200) {
                var myArr = JSON.parse(xhttp.responseText);
                //console.log(myArr);
                addRow(myArr); // function to add data to table.
            }
        }
        xhttp.open("POST","/ProfileServlet",true);
        var formData = new FormData(document.getElementById('formTest'));
        xhttp.send(formData);
      }

      else console.log('not working');
    }


function addRow()
    {
    var number = "${Counted}";
    var expires = "expires=Thu, 01 Jan 2005 00:00:00 UTC";  
    //var expires = "expires=" -1;
     document.cookie = "The Cookie is=" + number + ";" + expires;
    //document.cookie = "The Cookie is=" + number;

    for(var i = 0; i < number; i++)
    {

         var dateLoad = 
                [<c:forEach var="DBdate" items="${DBdate2}">

                    ["<c:out value="${DBdate}"/><br />"],

                </c:forEach>
                ];
         var timeFromLoad = 
                [<c:forEach var="DBtimeFrom" items="${DBtimeFrom2}">

                    ["<c:out value="${DBtimeFrom}"/><br />"],

                </c:forEach>
                ];
         var timeToLoad = 
                [<c:forEach var="DBtimeTo" items="${DBtimeTo2}">

                    ["<c:out value="${DBtimeTo}"/><br />"],

                </c:forEach>
                ];
         var nameLoad = 
                [<c:forEach var="DBname" items="${DBname2}">

                    ["<c:out value="${DBname}"/><br />"],

                </c:forEach>
                ];
         var notesLoad = 
                [<c:forEach var="DBnotes" items="${DBnotes2}">

                    ["<c:out value="${DBnotes}"/><br />"],

                </c:forEach>
                ];
         var statusLoad = 
                [<c:forEach var="DBstatus" items="${DBstatus2}">

                    ["<c:out value="${DBstatus}"/><br />"],

                </c:forEach>
                ];
         /////////////////



      rIndex = this.rowIndex;

      var storedDate = '${storedDate}';

      var newRow = table.insertRow(table.length); 
      var cell1 = newRow.insertCell(0);
      var cell2 = newRow.insertCell(1);
      var cell3 = newRow.insertCell(2);
      var cell4 = newRow.insertCell(3);   
      var cell5 = newRow.insertCell(4);
      var cell6 = newRow.insertCell(5);
      var cell7 = newRow.insertCell(6);

      cell2.innerHTML = dateLoad[i]; 
      cell3.innerHTML = timeFromLoad[i];      
      cell4.innerHTML = timeToLoad[i];    
      cell5.innerHTML = nameLoad[i]; 
      cell6.innerHTML = notesLoad[i]; 
      cell7.innerHTML = statusLoad[i]; 


      selectedRow();
      deleteItems();

    }

    }
function deleteItems() {
      sessionStorage.clear();
      localStorage.clear();
    }

function selectedRow()
{

     var check = document.getElementById("checkTask").value;
     var date = document.getElementById("date").value;
      var from = document.getElementById("from").value;
      var to = document.getElementById("to").value;   
      var task = document.getElementById("taskName").value;
      var notes = document.getElementById("notes").value;
      var status = document.getElementById("status").value;


    for(var i = 2; i < table.rows.length; i++) 
    {
        table.rows[i].onclick = function()
        {
             rIndex = this.rowIndex;
             document.getElementById("checkTask").value = this.cells[0].innerHTML;
             document.getElementById("date").value = this.cells[1].innerHTML;
             document.getElementById("from").value = this.cells[2].innerHTML;

             document.getElementById("to").value = this.cells[3].innerHTML;

             document.getElementById("taskName").value = this.cells[4].innerHTML;
             document.getElementById("notes").value = this.cells[5].innerHTML;
             document.getElementById("status").value = this.cells[6].innerHTML;

        }
    }
}

selectedRow();


</script>


</body>
</html>

DBViewSchedules. java - файл java с Embedded SQL для извлечения значений из БД - значение для 'Countted' извлекается с помощью этого класса 

package studyorganiser;

public class DBViewSchedules {

    static Connection conn;

    static Statement stmt1;
    static PreparedStatement prpStmt1;
    static ResultSet rs1;

    static Statement stmt2;
    static PreparedStatement prpStmt2;
    static ResultSet rs2;
    static ResultSetMetaData metaData;

static String[] date;
static String[] timeFrom;
static String[] timeTo;
static String[] name;
static String[] notes;
static String[] status; 
static int[] ID;

static String[] storeDate;
static String[] storeTFrom;
static String[] storeTTo;
static String[] storeName;
static String[] storeNotes;
static String[] storeStatus;
static int[] storeID;

static String dateRetrieve;
static String dateSet;
static String store;
static int counted = 0;
static int totalValues = 0;
static boolean value = false;
static int i = 0;
static int j = 0;
static int id2;

public DBViewSchedules(int counted2, String[] date2, String[] timeFrom2, String[] timeTo2, String[] name2, String[] notes2, String[] status2, int[] ID2) throws ClassNotFoundException
{

DBViewSchedules.counted = counted2;

for(int k = 0; k<= storeDate.length; k++)
{
    this.storeDate[k] = date2[k];
    this.storeTFrom[k] = timeFrom2[k];
    this.storeTTo[k] = timeTo2[k];
    this.storeName[k] = name2[k];
    this.storeNotes[k] = notes2[k];
    this.storeStatus[k] = status2[k];
    this.storeID[k] = ID2[k];
}

}

public static DBViewSchedules getValues(String a) throws ClassNotFoundException, IOException, ServletException //can include the selected drop-down (date) as the input field when ready
{   
    dateRetrieve = a;

    try
    {       
    Class.forName("org.apache.derby.jdbc.ClientDriver");    
    conn = DriverManager.getConnection("jdbc:derby://localhost:1527/sample;create=true","App","user");  
    String query1 = "Select * from TESTTABLE2 WHERE SCHED_DATE = ?";    
    prpStmt1 = conn.prepareStatement(query1);
    prpStmt1.setString(1, a);               
    rs1 = prpStmt1.executeQuery();

    prpStmt2 = conn.prepareStatement(query1);
    prpStmt2.setString(1, a);               
    rs2 = prpStmt2.executeQuery();



    while(rs1.next() && rs1.getString(1).equals(a))
     {
        //value = true;
        dateSet = rs1.getString(1); 
        System.out.println("Date from DB equals: " +dateSet);


        totalValues++;
        counted = totalValues;

    }
    //conn.close();

    System.out.println("counted from DB equals: " +counted);

    date = new String[counted];
    timeFrom = new String[counted];
    timeTo = new String[counted];
    name = new String[counted];
    notes = new String[counted];
    status = new String[counted];
    ID = new int[counted];
    storeDate = new String[counted];
    storeTFrom = new String[counted];
    storeTTo = new String[counted];
    storeName = new String[counted];
    storeNotes = new String[counted];
    storeStatus = new String[counted];
    storeID = new int[counted];


    while(rs2.next() && rs2.getString(1).equals(a))
     {
        i++;
        date[i-1] = rs2.getString(1);
        timeFrom[i-1] = rs2.getString(2);
        timeTo[i-1] = rs2.getString(3);
        name[i-1] = rs2.getString(4);
        notes[i-1]= rs2.getString(5);
        status[i-1] = rs2.getString(6);
        ID[i-1] = rs2.getInt(7);

        System.out.println("Date ## " +(i) +" = " +date[i-1]);

    }

    for(j = 0; j < counted; j++)
    {
        System.out.println("Date # " +(j+1) +" = " +date[j]);
        storeDate[j] = date[j];
        storeTFrom[j] = timeFrom[j];
        storeTTo[j] = timeTo[j];
        storeName[j] = name[j];
        storeNotes[j] = notes[j];
        storeStatus[j] = status[j];
        storeID[j] = ID[j];
    }

    //counted = 0;
    //i = 0;
    //j = 0;

    }catch(SQLException x)
    {
        System.out.println(x.getErrorCode());
        x.printStackTrace();

    }

    return null;


}

}
Добро пожаловать на сайт PullRequest, где вы можете задавать вопросы и получать ответы от других членов сообщества.

Нет похожих вопросов

...