Wie wirksame "alle auswählen" - checkbox in JSF

Ich implementieren möchten, wählen Sie alle Kontrollkästchen in JSF h:datatable. Dies ist der code, wenn die h:datatable:

<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"    
      xmlns:h="http://java.sun.com/jsf/html"
      xmlns:f="http://java.sun.com/jsf/core"
      xmlns:ui="http://java.sun.com/jsf/facelets">
    <h:head>
        <ui:insert name="header">           
            <ui:include src="header.xhtml"/>         
        </ui:insert>
    </h:head>
    <h:body>

        <h1><img src="resources/css/images/icon.png" alt="DX-57" /> History Center</h1>
        <!-- layer for black background of the buttons -->
        <div id="toolbar" style="margin: 0 auto; width:1180px; height:30px; position:relative;  background-color:black">
            <!-- Include page Navigation -->
            <ui:insert name="Navigation">           
                <ui:include src="Navigation.xhtml"/>         
            </ui:insert>

        </div>  

        <div id="logodiv" style="position:relative; top:35px; left:0px;"> 
            <h:graphicImage alt="Dashboard"  style="position:relative; top:-20px; left:9px;"  value="resources/images/logo_sessions.png" />
        </div>
        <div id="main" style="margin: 0 auto; width:1190px; height:700px; position:absolute;  background-color:transparent; top:105px">

            <div id="mainpage" style="margin: 0 auto; width:1190px; height:500px; position:absolute;  background-color:transparent; top:80px">

                <div id="settingsHashMap" style="width:750px; height:400px; position:absolute;  background-color:r; top:20px; left:1px">

                    <h:form id="form">

                        <ui:debug />

                        <!-- The sortable data table -->
                        <h:dataTable id="dataTable" value="#{SessionsController.dataList}" binding="#{table}" var="item">
                            <!-- Check box -->
                            <h:column>
                                <f:facet name="header">
                                    <h:outputText value="Select" />
                                </f:facet>
                                <h:selectBooleanCheckbox onclick="highlight(this)" value="#{SessionsController.selectedIds[item.aSessionID]}" />
                            </h:column>
                            <h:column>
                                <f:facet name="header">
                                    <h:commandLink value="№" actionListener="#{SessionsController.sort}">
                                        <f:attribute name="№" value="№" />
                                    </h:commandLink>
                                </f:facet>
                                <h:outputText value="#{table.rowIndex + SessionsController.firstRow + 1}" />
                            </h:column>
                            <h:column>
                                <f:facet name="header">
                                    <h:commandLink value="Account Session ID" actionListener="#{SessionsController.sort}">
                                        <f:attribute name="sortField" value="Account Session ID" />
                                    </h:commandLink>
                                </f:facet>
                                <h:outputText value="#{item.aSessionID}" />
                            </h:column>
                            <h:column>
                                <f:facet name="header">
                                    <h:commandLink value="User ID" actionListener="#{SessionsController.sort}">
                                        <f:attribute name="sortField" value="User ID" />
                                    </h:commandLink>
                                </f:facet>
                                <h:outputText value="#{item.userID}" />
                            </h:column>
                            <h:column>
                                <f:facet name="header">
                                    <h:commandLink value="Activity Start Time" actionListener="#{SessionsController.sort}">
                                        <f:attribute name="sortField" value="Activity Start Time" />
                                    </h:commandLink>
                                </f:facet>
                                <h:outputText value="#{item.activityStart}" />
                            </h:column>
                            <h:column>
                                <f:facet name="header">
                                    <h:commandLink value="Activity End Time" actionListener="#{SessionsController.sort}">
                                        <f:attribute name="sortField" value="Activity End Time" />
                                    </h:commandLink>
                                </f:facet>
                                <h:outputText value="#{item.activityEnd}" />
                            </h:column>
                            <h:column>
                                <f:facet name="header">
                                    <h:commandLink value="Activity" actionListener="#{SessionsController.sort}">
                                        <f:attribute name="sortField" value="Activity" />
                                    </h:commandLink>
                                </f:facet>
                                <h:outputText value="#{item.activity}" />
                            </h:column>
                        </h:dataTable>

                        <!-- The paging buttons -->
                        <h:commandButton value="first" action="#{SessionsController.pageFirst}"
                                         disabled="#{SessionsController.firstRow == 0}" >
                            <f:ajax render="@form" execute="@form"></f:ajax>
                        </h:commandButton>


                        <h:commandButton value="prev" action="#{SessionsController.pagePrevious}"
                                         disabled="#{SessionsController.firstRow == 0}" >
                            <f:ajax render="@form" execute="@form"></f:ajax>
                        </h:commandButton>

                        <h:commandButton value="next" action="#{SessionsController.pageNext}"
                                         disabled="#{SessionsController.firstRow + SessionsController.rowsPerPage >= SessionsController.totalRows}" >
                            <f:ajax render="@form" execute="@form"></f:ajax>
                        </h:commandButton>    

                        <h:commandButton value="last" action="#{SessionsController.pageLast}"
                                         disabled="#{SessionsController.firstRow + SessionsController.rowsPerPage >= SessionsController.totalRows}" >
                            <f:ajax render="@form" execute="@form"></f:ajax>
                        </h:commandButton>

                        <h:outputText value="Page #{SessionsController.currentPage} /#{SessionsController.totalPages}" />
                        <br />

                        <!-- The paging links -->
                        <ui:repeat value="#{SessionsController.pages}" var="page">
                            <h:commandLink value="#{page}" actionListener="#{SessionsController.page}"
                                           rendered="#{page != SessionsController.currentPage}" >
                                <f:ajax render="@form" execute="@form"></f:ajax>   
                            </h:commandLink>
                            <h:outputText value="#{page}" escape="false"
                                          rendered="#{page == SessionsController.currentPage}" />
                        </ui:repeat>
                        <br />

                        <!-- Set rows per page -->
                        <h:outputLabel for="rowsPerPage" value="Rows per page" />
                        <h:inputText id="rowsPerPage" value="#{SessionsController.rowsPerPage}" size="3" maxlength="3" />
                        <h:commandButton value="Set" action="#{SessionsController.pageFirst}" >
                            <f:ajax render="@form" execute="@form"></f:ajax>
                        </h:commandButton>
                        <h:message for="rowsPerPage" errorStyle="color: red;" />

                        <h:commandButton value="Delete" action="#{SessionsController.deleteSelectedIDs}" >

                        </h:commandButton>

                    </h:form>                  

                </div>   

                <div id="settingsdivb" style="width:350px; height:400px; position:absolute;  background-color:transparent; top:20px; left:800px">

                </div>   
            </div>  
        </div>
    </h:body>
</html>

Dies ist die managed bean:

package com.DX_57.HM_57;
/*
 * include default packages for Beans
 */

import java.io.Serializable;
import javax.enterprise.context.SessionScoped;
//or import javax.faces.bean.SessionScoped;
import javax.inject.Named;
/*
 * include SQL Packages
 */
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.*;
import javax.annotation.PostConstruct;
import javax.sql.DataSource;
import javax.annotation.Resource;
import javax.faces.bean.ViewScoped;
import javax.faces.component.UICommand;
import javax.faces.context.FacesContext;
import javax.inject.Inject;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
//or import javax.faces.bean.ManagedBean; 
import javax.faces.event.ActionEvent;

import org.glassfish.osgicdi.OSGiService;

@Named("SessionsController")
@ViewScoped
public class Sessions implements Serializable {

    /*
     * Call the Oracle JDBC Connection driver
     */
    @Resource(name = "jdbc/Oracle")
    private DataSource ds;
    //Data.
    private List<ActiveSessionObj> dataList;
    //Rows
    private int totalRows;
    //Paging.
    private int firstRow;
    private int rowsPerPage;
    private int totalPages;
    private int pageRange;
    private Integer[] pages;
    private int currentPage;
    //Sorting.
    private String sortField;
    private boolean sortAscending;

    /*
     * Constructor
     */
    public Sessions() {
        /*
         * Set default properties
         */
        rowsPerPage = 10; //Default rows per page (max amount of rows to be displayed at once).
        pageRange = 10; //Default page range (max amount of page links to be displayed at once).
        sortField = "ASESSIONID"; //Default sort field.
        sortAscending = true; //Default sort direction.
    }

    public class ActiveSessionObj {

        /*
         * Oracle table structure CREATE TABLE ACTIVESESSIONSLOG( ASESSIONID
         * VARCHAR2(30 ) NOT NULL, USERID VARCHAR2(30 ), ACTIVITYSTART
         * TIMESTAMP(6), ACTIVITYEND TIMESTAMP(6), ACTIVITY CLOB )
         */
        private String aSessionID;
        private String userID;
        private Date activityStart;
        private Date activityEnd;
        private String activity;
        //private boolean selected;

        public ActiveSessionObj(String aSessionID, String userID, Date activityStart, Date activityEnd, String activity) {
            this.aSessionID = aSessionID;
            this.userID = userID;
            this.activityStart = activityStart;
            this.activityEnd = activityEnd;
            this.activity = activity;
        }

        public int getFirstRow() {
            return firstRow;
        }

        public String getaSessionID() {
            return aSessionID;
        }

        public void setaSessionID(String aSessionID) {
            this.aSessionID = aSessionID;
        }

        public String getactivity() {
            return activity;
        }

        public void setactivity(String activity) {
            this.activity = activity;
        }

        public Date getactivityEnd() {
            return activityEnd;
        }

        public void setactivityEnd(Date activityEnd) {
            this.activityEnd = activityEnd;
        }

        public Date getactivityStart() {
            return activityStart;
        }

        public void setactivityStart(Date activityStart) {
            this.activityStart = activityStart;
        }

        public String getuserID() {
            return userID;
        }

        public void setuserID(String userID) {
            this.userID = userID;
        }

        private ActiveSessionObj() {
            throw new UnsupportedOperationException("Not yet implemented");
        }
    }

    //Paging actions -----------------------------------------------------------------------------
    public void pageFirst() {
        page(0);
    }

    public void pageNext() {
        page(firstRow + rowsPerPage);
    }

    public void pagePrevious() {
        page(firstRow - rowsPerPage);
    }

    public void pageLast() {
        page(totalRows - ((totalRows % rowsPerPage != 0) ? totalRows % rowsPerPage : rowsPerPage));
    }

    public void page(ActionEvent event) {
        page(((Integer) ((UICommand) event.getComponent()).getValue() - 1) * rowsPerPage);
    }

    private void page(int firstRow) {
        this.firstRow = firstRow;
        loadDataList(); //Load requested page.
    }

    //Sorting actions ----------------------------------------------------------------------------
    public void sort(ActionEvent event) {
        String sortFieldAttribute = (String) event.getComponent().getAttributes().get("sortField");

        //If the same field is sorted, then reverse order, else sort the new field ascending.
        if (sortField.equals(sortFieldAttribute)) {
            sortAscending = !sortAscending;
        } else {
            sortField = sortFieldAttribute;
            sortAscending = true;
        }

        pageFirst(); //Go to first page and load requested page.
    }

    //Loaders ------------------------------------------------------------------------------------
    private void loadDataList() {

        //Load list and totalCount.
        try {
            dataList = list(firstRow, rowsPerPage, sortField, sortAscending);
            totalRows = countDBRowNum(); //count the tablerows
        } catch (Exception e) {
            throw new RuntimeException(e);
        }

        //Set currentPage, totalPages and pages.
        currentPage = (totalRows / rowsPerPage) - ((totalRows - firstRow) / rowsPerPage) + 1;
        totalPages = (totalRows / rowsPerPage) + ((totalRows % rowsPerPage != 0) ? 1 : 0);
        int pagesLength = Math.min(pageRange, totalPages);
        pages = new Integer[pagesLength];

        //firstPage must be greater than 0 and lesser than totalPages-pageLength.
        int firstPage = Math.min(Math.max(0, currentPage - (pageRange / 2)), totalPages - pagesLength);

        //Create pages (page numbers for page links).
        for (int i = 0; i < pagesLength; i++) {
            pages[i] = ++firstPage;
        }
    }

    //Getters ------------------------------------------------------------------------------------
    public List<ActiveSessionObj> getdataList() {
        if (dataList == null) {
            loadDataList(); //Preload page for the 1st view.
        }
        return dataList;
    }

    public int getTotalRows() {
        return totalRows;
    }

    public int getFirstRow() {
        return firstRow;
    }

    public int getRowsPerPage() {
        return rowsPerPage;
    }

    public Integer[] getPages() {
        return pages;
    }

    public int getCurrentPage() {
        return currentPage;
    }

    public int getTotalPages() {
        return totalPages;
    }

    //Setters ------------------------------------------------------------------------------------
    public void setRowsPerPage(int rowsPerPage) {
        this.rowsPerPage = rowsPerPage;
    }

    //Actions ------------------------------------------------------------------------------------
    /**
     * Returns list of ActiveSessionObj items starting at the given first index
     * with the given row count, sorted by the given sort field and sort order.
     *
     * @param firstRow First index of rows to be returned.
     * @param rowCount Amount of rows to be returned.
     * @param sortField Field to sort the data on.
     * @param sortAscending Whether to sort data ascending or not.
     * @return list of ActiveSessionObj items starting at the given first index
     * with the given row count, sorted by the given sort field and sort order.
     * @throws DAOException If something fails at DAO level.
     */
    public List<ActiveSessionObj> list(int firstRow, int rowCount, String sortField, boolean sortAscending) throws SQLException {

        String SqlStatementSmall = null;
        String SQLStatementLarge = null;

        if (ds == null) {
            throw new SQLException();
        }

        Connection conn = ds.getConnection();
        if (conn == null) {
            throw new SQLException();
        }

        int countrow = firstRow + rowCount;
        String sortDirection = sortAscending ? "ASC" : "DESC";

        /*
         * For small tables
         */
        SqlStatementSmall = "SELECT c.*"
                + " FROM (SELECT b.*, rownum rn"
                + " FROM (SELECT a.*"
                + " FROM activeSessionsLog a"
                + " ORDER BY %s %s) b"
                + " WHERE rownum <= ?) c"
                + " WHERE rn > ?";

        /*
         * For huge datatables optimized for perfomance
         */
        SQLStatementLarge = "select * from"
                + " (select asl.*, row_number() over (order by userid asc) r "
                + " from activesessionslog asl)"
                + " where r > 980750 and r <= 980800;";


        String sql = String.format(SqlStatementSmall, sortField, sortDirection);

        PreparedStatement ps = null;
        ResultSet resultSet = null;
        List<ActiveSessionObj> dataList = new ArrayList<ActiveSessionObj>();

        try {
            conn.setAutoCommit(false);
            boolean committed = false;

            ps = conn.prepareStatement(sql);
            ps.setInt(1, countrow);
            ps.setInt(2, firstRow);


            resultSet = ps.executeQuery();
            /*
             * take the result from the SQL query and insert it into Array List
             * collection
             */
            dataList = ActiveSessionsArrayList(resultSet);

            conn.commit();
            committed = true;



        } finally {
            ps.close();
            conn.close();
        }

        return dataList;
    }

    /**
     * Returns total amount of rows in table.
     *
     * @return Total amount of rows in table.
     * @throws DAOException If something fails at DAO level.
     */
    public int countDBRowNum() throws Exception {

        String SqlStatement = null;

        if (ds == null) {
            throw new SQLException();
        }

        Connection conn = ds.getConnection();
        if (conn == null) {
            throw new SQLException();
        }

        SqlStatement = "SELECT count(*) FROM ACTIVESESSIONSLOG";

        PreparedStatement ps = null;
        ResultSet resultSet = null;
        int count = 0;

        try {
            conn.setAutoCommit(false);
            boolean committed = false;
            try {
                SqlStatement = "SELECT count(*) FROM ACTIVESESSIONSLOG";

                ps = conn.prepareStatement(SqlStatement);
                resultSet = ps.executeQuery();

                if (resultSet.next()) {
                    count = resultSet.getInt(1);
                }

                conn.commit();
                committed = true;
            } finally {
                if (!committed) {
                    conn.rollback();
                }
            }
        } finally {
            ps.close();
            conn.close();
        }

        return count;
    }

    /**
     * Map the current row of the given ResultSet to ActiveSessionObj.
     *
     * @param resultSet The ResultSet of which the current row is to be mapped
     * to ActiveSessionObj.
     * @return The mapped ActiveSessionObj from the current row of the given
     * ResultSet.
     * @throws SQLException If something fails at database level.
     */
    private ArrayList<ActiveSessionObj> ActiveSessionsArrayList(ResultSet rs) throws SQLException {
        ArrayList<ActiveSessionObj> list = new ArrayList<>();


        try {
            while (rs.next()) {
                list.add(new ActiveSessionObj(
                        rs.getString("ASESSIONID"),
                        rs.getString("USERID"),
                        timestampToDate(rs.getTimestamp("ACTIVITYSTART")),
                        timestampToDate(rs.getTimestamp("ACTIVITYEND")),
                        rs.getString("ACTIVITY")));
            }
        } catch (Exception x) {
            x.printStackTrace();
        }

        return list;   
    }

    //get the selected rows
    private HashMap<String, Boolean> selectedIds = new HashMap<>();

    //get the list from the JSF page
    public Map<String, Boolean> getSelectedIds() {
        return selectedIds;
    }

    //delete all selected checkboxes
    public void deleteSelectedIDs() throws SQLException {
        boolean success = false;

        if (ds == null) {
            throw new SQLException();
        }

        Connection conn = ds.getConnection();
        if (conn == null) {
            throw new SQLException();
        }

        PreparedStatement ps = null;
        ResultSet resultSet = null;

        try {
            conn.setAutoCommit(false);
            boolean committed = false;
            try {

                String sqlDeleteQuery = "DELETE FROM ACTIVESESSIONSLOG WHERE ASESSIONID = ?";


                Set<String> keySet = selectedIds.keySet();
                String[] keys = new String[]{};
                keys = selectedIds.keySet().toArray(keys);
                ps = conn.prepareStatement(sqlDeleteQuery);

                for (int i = 0; i < keys.length; i++) {
                    ps.setString(1, keys[i]);
                    ps.executeUpdate();
                    ps.clearParameters();
                    selectedIds.put(keys[i], false); //get(keys[i]) = false;
                }

                conn.commit();
                committed = true;

                //selectedIds.clear();
            } finally {
                if (!committed) {
                    conn.rollback();
                }
            }
        } finally {
            ps.close();
            conn.close();
        }

        /*
         * //Get selected items. boolean success = false; try { String
         * sqlDeleteQuery = "";
         *
         * Set<String> keySet = selectedIds.keySet(); Iterator keyIterator =
         * keySet.iterator(); while(keyIterator.hasNext()) { keyIterator.next();
         * }
         *
         * }
         * catch(Exception x) { success = false; } //Do your thing with the
         * MyData items in List selectedDataList.
         */
        //return success; //Navigation case.
    }


    private static Date timestampToDate(java.sql.Timestamp ts) {
        Date d = null;
        try {
            d = new Date(ts.getTime());
        } catch (Exception e) {
            e.printStackTrace();
        }

        return d;
    }
}

Meine Frage ist, wie kann ich implementieren Wahlfach select all - Taste. Eine Möglichkeit zum erstellen von java-Methode, die bekommt alle Schlüssel der Datenbank-Tabelle, und erstellen Sie hashmap speichert alle Schlüssel. So etwas wie dieses:

private HashMap<String, Boolean> selectedIds = new HashMap<>();

Dieser code funktioniert sehr gut, wenn ich versuchte, Sie zu implementieren, wählen Sie die Zeile mit Kontrollkästchen. Das problem ist, was passiert, wenn ich eine million Zeilen oder mehr in den in der Datenbank-Tabelle? In diesem Fall werden alle Tasten eingefügt werden, in einem sehr großen hashmap und vielleicht bekomme ich Fehler, weil der Speicherbedarf zu groß. Gibt es mehr optimierte Lösung?

Die besten Wünsche
Peter

UPDATE

Habe ich umgesetzt einfaches Kontrollkästchen für die Auswahl von Zeilen und Weitergabe zu löschen, die java-Methode ist, löschen Sie die Zeilen in die Datenbank Tabelle mit dem Schlüssel. Aber wie kann ich implementieren select all in JavaScript-client-Seite, und rufen Sie die java-Methode, die löscht alle Datensätze aus der Datenbank-Tabelle?

Gibt es einen Grund, warum Sie brauchen, um über die Fähigkeiten für eine million Zeilen in der Tabelle? Ich habe das Gefühl, der browser würde choke ziemlich gut, nur die Anzeige der Informationen, geschweige denn, die Rücksendung-Antwort an das servlet.
Suchen Sie bei Google. Gibt es die Unmenge der Ergebnisse zurück in eine einzige Antwort? Nein, es gibt nur eine Teilmenge der Ergebnisse, basierend auf filtern (das Suchfeld) und die Paginierung (die paging-Schaltflächen). Auf diese Weise haben Sie letztendlich nur eine begrenzte Teilmenge der Datensätze in den Speicher. Komponenten-Bibliotheken wie PrimeFaces bieten komplette ready-to-use-Lösungen für diese, so dass Sie brauchen nicht das Rad neu zu erfinden.
vielleicht werde ich es niemals nötig haben, eine million Zeilen, aber ich möchte design die JSF-Tabelle zu Bearbeiten.

InformationsquelleAutor Peter Penzov | 2012-05-14

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