Ich habe Jsf-Webseite, das ist einige Strings-Abfrage von vorherigen Seiten.

Mein Problem ist, dass diese Hauptseite zwischengespeicherte Werte zu haben scheint, keine Änderung. Auch wenn ich diese Werte in null geändert habe, soll sie eine leere Seite erhalten, aber einen älteren Wert.

Also lautet mein F: Wie kann ich meine Haupt-JSF-Seite jedes Mal neu laden oder den Cache löschen lassen, wenn ich sie aufrufe oder die F-Taste drücke?

Mein JSF-Beispielcode, den ich ausprobiert habe:

     <h:head style="width: 200px; ">
    <f:facet name="first">
        <meta http-equiv="X-UA-Compatible" content="edge, chrome=1" />
        <meta http-equiv="Cache-Control" content="no-cache, no-store, must-revalidate" />
<meta http-equiv="Pragma" content="no-cache" />
<meta http-equiv="Expires" content="-1" />
    </f:facet>

Java-Klasse:

String SID = FacesContext.getCurrentInstance().getExternalContext()
        .getRequestParameterMap().get("SID");

String from = FacesContext.getCurrentInstance().getExternalContext()
        .getRequestParameterMap().get("from");

String to = FacesContext.getCurrentInstance().getExternalContext()
        .getRequestParameterMap().get("to");

String class_id = FacesContext.getCurrentInstance()
        .getExternalContext().getRequestParameterMap().get("class_id");


if (SID==null) {
    try {
        Dbconnection NewConnect = new Dbconnection();
        Connection con = NewConnect.MakeConnect();
        Statement stmt = con.createStatement();
        ResultSet rs = stmt
                .executeQuery("SELECT a.course_id, a.teacher_id, a.class_id, a.day_id, a.state, a.apssent_date, a.interval_id,s.student_id,s.first_name FROM student AS s INNER JOIN apsent AS a ON s.student_id = a.student_id where apssent_date between '"
                        + from
                        + "' and '"
                        + to
                        + "' and a.class_id = "
                        + Integer.parseInt(class_id));


        while (rs.next()) {

            ids.add(rs.getInt(8));
            names.add(rs.getString(9));
            intervals.add(rs.getInt(7));
            teachers.add(rs.getInt(2));
            dates.add(rs.getString(6));
            state.add(rs.getString(5));
        }

    } catch (Exception ex) {

        System.out.println(ex);
    }
}

System.out.println(SID + from + class_id + to);

if (class_id==null) {

    try {
        Dbconnection NewConnect = new Dbconnection();
        Connection con = NewConnect.MakeConnect();
        Statement stmt = con.createStatement();
        ResultSet rs = stmt
                .executeQuery("SELECT a.course_id, a.teacher_id, a.class_id, a.day_id, a.state, a.apssent_date, a.interval_id,s.student_id,s.first_name FROM student AS s INNER JOIN apsent AS a ON s.student_id = a.student_id where apssent_date between '"
                        + from
                        + "' and '"
                        + to
                        + "' and s.student_id = " + SID);

        while (rs.next()) {
            // System.out.println(rs.getInt(1));

            ids.add(rs.getInt(8));
            names.add(rs.getString(9));
            intervals.add(rs.getInt(7));
            teachers.add(rs.getInt(2));
            dates.add(rs.getString(6));
            state.add(rs.getString(5));
        }



    } catch (Exception ex) {

        System.out.println(ex);
    }

}

carsSmall = new ArrayList<Car>();
populateRandomCars(carsSmall, ids.size(), ids, names,
        intervals, teachers, dates, state);

}