ComboBox-Items with remembering checkboxes

Hello dear stackoverflow,

I tried to do some new things in java and actual I can't solve this problem with my own knowledge.

Myself is programming an application for gardening. The user can select a fertilizer from a combobox and add the hook in the checkboxes (monday to sunday) whenever the plants are feedet.

If he is finished with editing the days of feeding the plants then the user can select another fertilizer from the combobox.

Now I will try that pro fertilizer in the combobox the day-checkboxes are unique for the fertilizer which is selected from the combobox. I mean when the user is switching between the fertilizers in the combobox, that the checkboxes are correctly restored to the state of editing for every fertilizer in the Combobox.

Did you know any idea how I can implement this?

public class JPanelDuenger extends javax.swing.JPanel {

//Getter-CheckBox-Montag
public boolean isMontag() {
    boolean rueckgabe;
    rueckgabe = (Boolean) jCheckBoxMontag.isSelected();
    return rueckgabe;
}

//Getter-CheckBox-Dienstag
public boolean isDienstag() {
    boolean rueckgabe;
    rueckgabe = (Boolean) jCheckBoxDienstag.isSelected();
    return rueckgabe;
}

//Getter-CheckBox-Mittwoch
public boolean isMittwoch() {
    boolean rueckgabe;
    rueckgabe = (Boolean) jCheckBoxMittwoch.isSelected();
    return rueckgabe;
}

//Getter-CheckBox-Donnerstag
public boolean isDonnerstag() {
    boolean rueckgabe;
    rueckgabe = (Boolean) jCheckBoxDonnerstag.isSelected();
    return rueckgabe;
}

//Getter-CheckBox-Freitag
public boolean isFreitag() {
    boolean rueckgabe;
    rueckgabe = (Boolean) jCheckBoxFreitag.isSelected();
    return rueckgabe;
}

//Getter-CheckBox-Samstag
public boolean isSamstag() {
    boolean rueckgabe;
    rueckgabe = (Boolean) jCheckBoxSamstag.isSelected();
    return rueckgabe;
}

//Getter-CheckBox-Sonntag
public boolean isSonntag() {
    boolean rueckgabe;
    rueckgabe = (Boolean) jCheckBoxSonntag.isSelected();
    return rueckgabe;
}

//Getter-CheckBox-Dünger
public String getDuengerName() {
    String rueckgabe;
    rueckgabe = (String)jComboBoxDuenger.getSelectedItem();
    return rueckgabe;
}

//Getter-Spinner-Dünger
public double getDuengerMilliliter() {
    double rueckgabe;
    rueckgabe = (Double)jSpinnerDuenger.getValue();
    return rueckgabe;
}

public JPanelDuenger() {
    initComponents();
}

@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

    jPanelHintergrund = new javax.swing.JPanel();
    jLabelDuenger = new javax.swing.JLabel();
    jComboBoxDuenger = new javax.swing.JComboBox<>();
    jSpinnerDuenger = new javax.swing.JSpinner();
    jLabelDuengerMilliliter = new javax.swing.JLabel();
    jCheckBoxMontag = new javax.swing.JCheckBox();
    jCheckBoxDienstag = new javax.swing.JCheckBox();
    jCheckBoxMittwoch = new javax.swing.JCheckBox();
    jCheckBoxDonnerstag = new javax.swing.JCheckBox();
    jCheckBoxFreitag = new javax.swing.JCheckBox();
    jCheckBoxSamstag = new javax.swing.JCheckBox();
    jCheckBoxSonntag = new javax.swing.JCheckBox();

    setBackground(new java.awt.Color(153, 153, 153));

    jLabelDuenger.setText("Dünger:");

    jComboBoxDuenger.setModel(new javax.swing.DefaultComboBoxModel<>(new String[] { "Item 1", "Item 2", "Item 3", "Item 4" }));

    jSpinnerDuenger.setModel(new javax.swing.SpinnerNumberModel(0.0d, 0.0d, 1000.0d, 0.1d));

    jLabelDuengerMilliliter.setText("ml");

    jCheckBoxMontag.setText("MO");

    jCheckBoxDienstag.setText("DI");

    jCheckBoxMittwoch.setText("MI");

    jCheckBoxDonnerstag.setText("DO");

    jCheckBoxFreitag.setText("FR");

    jCheckBoxSamstag.setText("SA");

    jCheckBoxSonntag.setText("SO");

    javax.swing.GroupLayout jPanelHintergrundLayout = new javax.swing.GroupLayout(jPanelHintergrund);
    jPanelHintergrund.setLayout(jPanelHintergrundLayout);
    jPanelHintergrundLayout.setHorizontalGroup(
        jPanelHintergrundLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(jPanelHintergrundLayout.createSequentialGroup()
            .addContainerGap()
            .addGroup(jPanelHintergrundLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanelHintergrundLayout.createSequentialGroup()
                    .addComponent(jCheckBoxMontag)
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                    .addComponent(jCheckBoxDienstag, javax.swing.GroupLayout.PREFERRED_SIZE, 41, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                    .addComponent(jCheckBoxMittwoch, javax.swing.GroupLayout.PREFERRED_SIZE, 41, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGroup(jPanelHintergrundLayout.createSequentialGroup()
                    .addComponent(jCheckBoxDonnerstag)
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                    .addComponent(jCheckBoxFreitag, javax.swing.GroupLayout.PREFERRED_SIZE, 41, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                    .addComponent(jCheckBoxSamstag, javax.swing.GroupLayout.PREFERRED_SIZE, 41, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                    .addComponent(jCheckBoxSonntag, javax.swing.GroupLayout.PREFERRED_SIZE, 41, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addComponent(jLabelDuenger)
                .addGroup(jPanelHintergrundLayout.createSequentialGroup()
                    .addComponent(jComboBoxDuenger, javax.swing.GroupLayout.PREFERRED_SIZE, 104, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                    .addComponent(jSpinnerDuenger, javax.swing.GroupLayout.PREFERRED_SIZE, 43, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                    .addComponent(jLabelDuengerMilliliter)))
            .addContainerGap(19, Short.MAX_VALUE))
    );
    jPanelHintergrundLayout.setVerticalGroup(
        jPanelHintergrundLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(jPanelHintergrundLayout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jLabelDuenger)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
            .addGroup(jPanelHintergrundLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                .addComponent(jComboBoxDuenger, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addComponent(jSpinnerDuenger, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addComponent(jLabelDuengerMilliliter))
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
            .addGroup(jPanelHintergrundLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                .addComponent(jCheckBoxMontag)
                .addComponent(jCheckBoxDienstag)
                .addComponent(jCheckBoxMittwoch))
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
            .addGroup(jPanelHintergrundLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                .addComponent(jCheckBoxDonnerstag)
                .addComponent(jCheckBoxFreitag)
                .addComponent(jCheckBoxSamstag)
                .addComponent(jCheckBoxSonntag))
            .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
    );

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
    this.setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jPanelHintergrund, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
            .addContainerGap())
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jPanelHintergrund, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
    );
}// </editor-fold>                        
// Variables declaration - do not modify                     
private javax.swing.JCheckBox jCheckBoxDienstag;
private javax.swing.JCheckBox jCheckBoxDonnerstag;
private javax.swing.JCheckBox jCheckBoxFreitag;
private javax.swing.JCheckBox jCheckBoxMittwoch;
private javax.swing.JCheckBox jCheckBoxMontag;
private javax.swing.JCheckBox jCheckBoxSamstag;
private javax.swing.JCheckBox jCheckBoxSonntag;
private javax.swing.JComboBox<String> jComboBoxDuenger;
private javax.swing.JLabel jLabelDuenger;
private javax.swing.JLabel jLabelDuengerMilliliter;
private javax.swing.JPanel jPanelHintergrund;
private javax.swing.JSpinner jSpinnerDuenger;
// End of variables declaration                   

} jPanel