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java swing Jframe not showing up correctly

Everything looks ok to me but for some reason, nothing is showing up properly, maybe I missed something but I'm not sure why it's not working, can someone help me out?
** task **
Improve your program by adding two
combo boxes in the frame. Through the combo boxes, the user should be able to
select their preferred fonts and font sizes. The displayed text will then be updated
accordingly (see the figure below).
Here is what its suppose to look like
import javax.swing.*;
import java.awt.BorderLayout;
import java.awt.Dimension;
import javax.swing.JTextField;
import java.awt.*;
import java.awt.event.*;
public class ComboGUI extends JFrame implements ActionListener {
public JButton update;
public JTextField textField;
public JLabel textLabel;
public JComboBox<String> fontBox;
public JComboBox sizeBox;
public String font;
public String size;
public ComboGUI()
{
components();
panels();
actionListener();
}
public void components()
{
this.update = new JButton("update");
this.textField=new JTextField(20);
this.textField.setText("hello");
this.textLabel= new JLabel("GUI");
this.font="Arial";
this.size="20";
this.textLabel.setFont(new Font(this.font, Font.PLAIN, Integer.parseInt(this.size)));
this.fontBox=new JComboBox();
this.fontBox.addItem("Times New Roman");
this.fontBox.addItem("Calibri");
this.sizeBox= new JComboBox();
this.sizeBox.addItem("20");
this.sizeBox.addItem("30");
this.sizeBox.addItem("40");
this.setSize(400, 400);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setLocationRelativeTo(null);
}
public void panels(){
JPanel northPanel =new JPanel();
JLabel fontLabel =new JLabel("Font: ");
JLabel sizeLabel =new JLabel("size: ");
northPanel.add(fontLabel);
//center
BGPanel centerPanel =new BGPanel();
centerPanel.add(this.textLabel);
this.add(centerPanel,BorderLayout.CENTER);
//south
BGPanel southPanel =new BGPanel();
southPanel.add(this.textLabel);
this.add(southPanel,BorderLayout.CENTER);
}
public void actionListener(){
this.update.addActionListener(this);
this.fontBox.addActionListener(this);
this.sizeBox.addActionListener(this);
}
#Override
public void actionPerformed(ActionEvent e){
if(e.getSource()==this.update){
this.textLabel.setText(this.textField.getText());
}
if(e.getSource()==this.fontBox || e.getSource()==this.sizeBox){
this.font=this.fontBox.getSelectedItem().toString();
this.size=this.sizeBox.getSelectedItem().toString();
this.textLabel.setFont(new Font(this.font,Font.PLAIN,Integer.parseInt(this.size)));
}
this.repaint();
}
public static void main(String[] args) {
ComboGUI comb =new ComboGUI();
combo.setVisible(true);
}
}
this is what im getting instead

It looks like you are missing this.setVisible(true); at the end of your constructor.
Your code should look like this:
public ComboGUI()
{
components();
panels();
actionListener();
this.setVisible(true);
}

incase anyone is trying to do something similar, this is the complete solution
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import java.awt.BorderLayout;
import javax.swing.JButton;
import javax.swing.JComboBox;
public class ComboGUI extends JFrame implements ActionListener{
public void updateLabelText(){
size = fSize.getItemAt(fSize.getSelectedIndex());
font = fStyles.getItemAt(fStyles.getSelectedIndex());
updateLabel.setFont(new Font(font,Font.PLAIN,size));
}
public static BGPanel centrePanel;
public JComboBox<String> fStyles;
public JComboBox<Integer> fSize;
public JButton updateButton;
public JLabel updateLabel;
public JLabel fontLabel;
public JLabel sizeLabel;
public JTextField textField;
public JPanel BottomPanel;
public JPanel topPanel;
private String font;
private int size;
public ComboGUI() {
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setSize(400,400);
this.setLocation(0, 0);
//Top
topPanel = new JPanel();
fontLabel = new JLabel("Font:");
sizeLabel = new JLabel("Font Size:");
fStyles = new JComboBox<String>();
fStyles.addItem("Arial");
fStyles.addItem("TimesRoman");
fStyles.addItem("Serif");
fStyles.addItem("Monospaced");
fStyles.addActionListener(this);
fSize = new JComboBox<Integer>();
fSize.addItem(10);
fSize.addItem(20);
fSize.addItem(30);
fSize.addItem(40);
fSize.addActionListener(this);
topPanel.add(fontLabel);
topPanel.add(fStyles);
topPanel.add(sizeLabel);
topPanel.add(fSize);
//CentrePanel setup
centrePanel = new BGPanel();
updateLabel = new JLabel("I love PDC :)");
centrePanel.add(updateLabel);
//Bottom
BottomPanel = new JPanel();
updateButton = new JButton("Update");
textField = new JTextField(20);
textField.setText("I love PDC :)");
updateButton.addActionListener(this);
BottomPanel.add(textField);
BottomPanel.add(updateButton);
this.add(centrePanel,BorderLayout.CENTER);
this.add(BottomPanel,BorderLayout.SOUTH);
this.add(topPanel,BorderLayout.NORTH);
updateLabelText();
}
public static void main(String[] args) {
ComboGUI combo = new ComboGUI();
combo.setVisible(true);
}
#Override
public void actionPerformed(ActionEvent e) {
if(e.getSource() == updateButton){
updateLabel.setText(textField.getText().trim());
}
if(e.getSource() == fStyles){
updateLabelText();
}
if (e.getSource() == fSize){
updateLabelText();
}
}
}

How to pass value JList item from JFrame into another JFrame (just value)?

I have write a test with two class.
The first JPanel, Gestion: JFrame with jlist + button (the button open the Jlist 2, PanelTest)
The second JPanel, PanelTest: JFrame and I want to recover in String, the select value item in the JFrame Gestion (JList)
How to do that ?
Gestion.java:
package IHM;
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.List;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.event.DocumentListener;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import javax.swing.JList;
import javax.swing.JButton;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.sql.SQLException;
public class Gestion extends JFrame {
private DocumentListener myListener;
public String test;
private JPanel contentPane;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
Gestion frame = new Gestion();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
public String getTest() {
return test;
}
/**
* Create the frame.
* #throws Exception
*/
public Gestion() throws Exception {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 300);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(0, 0));
setContentPane(contentPane);
final PanelTest panel2 = new PanelTest();
JPanel panel = new JPanel();
contentPane.add(panel, BorderLayout.NORTH);
String choix[] = {" Pierre", " Paul", " Jacques", " Lou", " Marie"};
final JList list = new JList(choix);
panel.add(list);
list.addListSelectionListener(new ListSelectionListener() {
public void valueChanged(ListSelectionEvent arg0) {
test = (String) list.getSelectedValue();
System.out.println(test);
// PanelTest.setValue(test);
}
});
JPanel panel_1 = new JPanel();
contentPane.add(panel_1, BorderLayout.SOUTH);
JButton btnNewButton = new JButton("New button");
btnNewButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
new PanelTest().setVisible(true);
fermerFenetre();
}
});
panel_1.add(btnNewButton);
}
public void fermerFenetre(){
this.setVisible(false);
}
}
PanelTest.java
package IHM;
import java.awt.BorderLayout;
public class PanelTest extends JFrame {
public String tyty;
private JPanel contentPane;
private JTextField textField;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
PanelTest frame = new PanelTest();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the frame.
*/
public PanelTest() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 300);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(0, 0));
setContentPane(contentPane);
textField = new JTextField();
contentPane.add(textField, BorderLayout.WEST);
textField.setColumns(10);
}
}

Suggestions:
Make your list variable a field, not a local variable, or else make it a final local variable so that it is accessible inside of the anonymous ActionListener.
Obtain the selected list item in your ActionListener where you launch the 2nd window.
Pass that String into your PanelTest object via a String parameter.
The second window should be a dialog such as a JDialog, not a JFrame.
As an aside, you'll rarely want to have your GUI classes extend top level windows such as JFrames or JDialogs as that greatly limits the flexibility of your GUI code.
For example,
import java.awt.Component;
import java.awt.Dialog.ModalityType;
import java.awt.Window;
import java.awt.event.ActionEvent;
import javax.swing.*;
#SuppressWarnings("serial")
public class Gestion2 extends JPanel {
private static final String CHOIX[] = { " Pierre", " Paul", " Jacques",
" Lou", " Marie" };
private JList<String> choixList = new JList<>(CHOIX);
public Gestion2() {
JPanel listPanel = new JPanel();
listPanel.add(new JScrollPane(choixList));
JPanel btnPanel = new JPanel();
btnPanel.add(new JButton(new ListSelectAction("Select Item and Press")));
setLayout(new BoxLayout(this, BoxLayout.PAGE_AXIS));
add(listPanel);
add(btnPanel);
}
private class ListSelectAction extends AbstractAction {
public ListSelectAction(String name) {
super(name);
}
#Override
public void actionPerformed(ActionEvent e) {
String selectedItem = choixList.getSelectedValue();
if (selectedItem != null) {
PanelTest2 panelTest2 = new PanelTest2(selectedItem);
Component component = (Component) e.getSource();
Window win = SwingUtilities.getWindowAncestor(component);
// JOptionPane example
JOptionPane.showMessageDialog(win, panelTest2,
"JOptionPane Example", JOptionPane.PLAIN_MESSAGE);
// or JDialog example
JDialog dialog = new JDialog(win, "JDialog Example",
ModalityType.APPLICATION_MODAL);
dialog.add(panelTest2);
dialog.pack();
dialog.setLocationRelativeTo(win);
dialog.setVisible(true);
}
}
}
private static void createAndShowGui() {
Gestion2 mainPanel = new Gestion2();
JFrame frame = new JFrame("Gestion2");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
#SuppressWarnings("serial")
class PanelTest2 extends JPanel {
private String selectedItem;
private JTextField textField = new JTextField(10);
public PanelTest2(String selectedItem) {
this.selectedItem = selectedItem;
textField.setText(selectedItem);
add(new JLabel("Selected Item:"));
add(textField);
}
public String getSelectedItem() {
return selectedItem;
}
}

Adding Text In a New Window

I'm in a bit of a situation here.I'm making a new program, when you click on the menu bar it opens a new window for the Licence, now here is the problem, how would I add text into that new window, here is my code for the new window:
JFrame frame = new JFrame("Licence");
frame.setSize(500,120);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
I know this is a easy question, I just can't think of the correct code for it.

You can try something like
JDialog dialog = new JDialog(your_frame_reference, "Licence");
dialog .setModal(true);
dialog .setLocationRelativeTo(null);
dialog. getContentPane().add(new JLabel(your_text);
dialog .setVisible(true);

You can use label
JFrame frame = new JFrame("Licence");
JLabel label = new JLabel("Text-Only Label");
label.setFont(new Font("Serif", Font.PLAIN, 36));
frame.add(label);

You can add text by creating JLabels like so:
JLabel label = new JLabel("Hello World");
This can then be added to your JFrame.

Try this Example
import java.awt.BorderLayout;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class TestDialog {
protected static void initUI() {
JPanel pane = newPane("Label in frame");
JFrame frame = new JFrame("Title");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(pane);
frame.pack();
frame.setVisible(true);
}
public static JPanel newPane(String labelText) {
JPanel pane = new JPanel(new BorderLayout());
pane.add(newLabel(labelText));
pane.add(newButton("Open dialog"), BorderLayout.SOUTH);
return pane;
}
private static JButton newButton(String label) {
final JButton button = new JButton(label);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
Window parentWindow = SwingUtilities.windowForComponent(button);
JDialog dialog = new JDialog(parentWindow);
dialog.setLocationRelativeTo(button);
dialog.setModal(true);
dialog.add(newPane("Label in dialog"));
dialog.pack();
dialog.setVisible(true);
}
});
return button;
}
private static JLabel newLabel(String label) {
JLabel l = new JLabel(label);
l.setFont(l.getFont().deriveFont(24.0f));
return l;
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
initUI();
}
});
}
}

Java Swings Select Tab

I have 4 JPanels. In one of the panel I have a combo Box.Upon selecting "Value A" in combo box Panel2 should be displayed.Similarly if I select "Value B" Panel3 should be selected....
Though action Listener should be used in this context.How to make a call to another tab with in that action listener.
public class SearchComponent
{
....
.
public SearchAddComponent(....)
{
panel = addDropDown(panelList(), "panel", gridbag, h6Box);
panel.addComponentListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
ItemSelectable is = (ItemSelectable)actionEvent.getSource();
Object name=selectedString(is);
}
});
}
public static final Vector<String> panelList(){
List<String> panelList = new ArrayList<String>();
panelList.add("A");
panelList.add("B");
panelList.add("C");
panelList.add("D");
panelList.add("E");
panelList.add("F);
Vector<String> panelVector = null;
Collections.copy(panelVector, panelList);
return panelVector;
}
public Object selectedString(ItemSelectable is) {
Object selected[] = is.getSelectedObjects();
return ((selected.length == 0) ? "null" : (ComboItem)selected[0]);
}
}

Use a Card Layout. See the Swing tutorial on How to Use a Card Layout for a working example.

Try This code:
import java.awt.EventQueue;
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Color;
import javax.swing.BorderFactory;
import javax.swing.border.Border;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JComboBox;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.SwingConstants;
import java.awt.Container;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class CardLayoutExample {
JFrame guiFrame;
CardLayout cards;
JPanel cardPanel;
public static void main(String[] args) {
//Use the event dispatch thread for Swing components
EventQueue.invokeLater(new Runnable()
{
#Override
public void run()
{
new CardLayoutExample();
}
});
}
public CardLayoutExample()
{
guiFrame = new JFrame();
//make sure the program exits when the frame closes
guiFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
guiFrame.setTitle("CardLayout Example");
guiFrame.setSize(400,300);
//This will center the JFrame in the middle of the screen
guiFrame.setLocationRelativeTo(null);
guiFrame.setLayout(new BorderLayout());
//creating a border to highlight the JPanel areas
Border outline = BorderFactory.createLineBorder(Color.black);
JPanel tabsPanel = new JPanel();
tabsPanel.setBorder(outline);
JButton switchCards = new JButton("Switch Card");
switchCards.setActionCommand("Switch Card");
switchCards.addActionListener(new ActionListener()
{
#Override
public void actionPerformed(ActionEvent event)
{
cards.next(cardPanel);
}
});
tabsPanel.add(switchCards);
guiFrame.add(tabsPanel,BorderLayout.NORTH);
cards = new CardLayout();
cardPanel = new JPanel();
cardPanel.setLayout(cards);
cards.show(cardPanel, "Fruits");
JPanel firstCard = new JPanel();
firstCard.setBackground(Color.GREEN);
addButton(firstCard, "APPLES");
addButton(firstCard, "ORANGES");
addButton(firstCard, "BANANAS");
JPanel secondCard = new JPanel();
secondCard.setBackground(Color.BLUE);
addButton(secondCard, "LEEKS");
addButton(secondCard, "TOMATOES");
addButton(secondCard, "PEAS");
cardPanel.add(firstCard, "Fruits");
cardPanel.add(secondCard, "Veggies");
guiFrame.add(tabsPanel,BorderLayout.NORTH);
guiFrame.add(cardPanel,BorderLayout.CENTER);
guiFrame.setVisible(true);
}
//All the buttons are following the same pattern
//so create them all in one place.
private void addButton(Container parent, String name)
{
JButton but = new JButton(name);
but.setActionCommand(name);
parent.add(but);
}
}

how to change UI depending on combo box selection

In dialog I need to display one group of controls if some combo is checked and another group of controls otherwise.
I.e. I need 2 layers and I need to switch between them when combo is checked/unchecked. How can I do that?
Thanks

CardLayout works well for this, as suggested below.
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
/** #see http://stackoverflow.com/questions/6432170 */
public class CardPanel extends JPanel {
private static final Random random = new Random();
private static final JPanel cards = new JPanel(new CardLayout());
private static final JComboBox combo = new JComboBox();
private final String name;
public CardPanel(String name) {
this.name = name;
this.setPreferredSize(new Dimension(320, 240));
this.setBackground(new Color(random.nextInt()));
this.add(new JLabel(name));
}
#Override
public String toString() {
return name;
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
create();
}
});
}
private static void create() {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
for (int i = 1; i < 9; i++) {
CardPanel p = new CardPanel("Panel " + String.valueOf(i));
combo.addItem(p);
cards.add(p, p.toString());
}
JPanel control = new JPanel();
combo.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
JComboBox jcb = (JComboBox) e.getSource();
CardLayout cl = (CardLayout) cards.getLayout();
cl.show(cards, jcb.getSelectedItem().toString());
}
});
control.add(combo);
f.add(cards, BorderLayout.CENTER);
f.add(control, BorderLayout.SOUTH);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
}