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Reusing a Button in Java Makes Nothing Display

I am really new to GUI programming in Java so please forgive me if this code is really basic. In short, I want to have 2 panels that are the same design. After I press the "A" button on the panel 1, I want to make panel 2 appear with the same design. Making the GUI efficient or pretty doesn't currently matter to me. I just want it to work. I have parts of the code listed below.
JButton buttonA = new JButton("a");
JButton buttonB = new JButton("b");
JButton buttonC = new JButton("c");
JButton buttonD = new JButton("d");
JPanel pan1 = new JPanel();
JPanel pan2 = new JPanel();
setTitle ("Test");
setSize (640, 640);
setResizable(false);
GridLayout grid1 = new GridLayout();
setLayout (grid1);
FlowLayout flow1 = new FlowLayout();
pan1.setLayout (flow1);
pan1.add(buttonA);
pan1.add(buttonB);
pan1.add(buttonC);
pan1.add(buttonD);
buttonA.addActionListener(this);
buttonB.addActionListener(this);
buttonC.addActionListener(this);
buttonD.addActionListener(this);
FlowLayout flow2 = new FlowLayout();
pan2.setLayout (flow2);
pan2.add(buttonA);
pan2.add(buttonB);
pan2.add(buttonC);
pan2.add(buttonD);
add(pan1);
add(pan2);
pan1.setVisible(true);
pan2.setVisible(false);
setVisible(true);
public void actionPerformed(ActionEvent event) {
if (command.equals("a")){//i want to show the panel 2 after button a is pressed
System.out.println("HelloA");
pan1.setVisible(false);
pan2.setVisible(true);
}
Currently, it just shows nothing in the window. Any help guys?

Short answer is, you can't.
Long answer is, a component can only reside on a single parent. Adding a component to a second container will automatically remove it from the first container before its added to the new one.
Instead, you will need to create individual buttons for both containers.
Also, understand that BorderLayout can't support what you're trying to do, it will only manage one component at a time (in each of the 5 available positions)
A better solution would be to make use of the CardLayout which is designed to facilitate the action you are trying to achieve

How to set Layout with another class in Java?

I'm writing a programm with a complicated TabbedPane, with lots of elements. Since I hit the Byte-limit in one of my classes, I decided to split the class into Initialisation/Button Listeners and the actual GridBagLayout. But now I'm having trouble getting it to work. My Main Class looks like this:
public class Main{
JFrame mainFrame = new JFrame("");
JTabbedPane tabpane = new JTabbedPane();
JPanel panelTab1 = new Tab1();
JScrollPane scrollTab2 = new JScrollPane(new Tab2());
JScrollPane scrollTab3 = new JScrollPane(new Tab3());
JPanel panelTab4 = new Tab4();
JMenuBar bar = new MenuBar();
public Main(){
tabpane.add("Tab1", panelTab1);
tabpane.add("Tab2", scrollTab2);
tabpane.add("Tab3", scrollTab3);
tabpane.add("Tab4", panelTab4);
mainFrame.getContentPane().add(tabpane);
mainFrame.setSize(1920,1080);
mainFrame.setExtendedState(JFrame.MAXIMIZED_BOTH);
mainFrame.setVisible(true);
mainFrame.validate();
mainFrame.setJMenuBar(bar);
}
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable(){
public void run(){
new Main();
}
});
}}
Tab3 is the culprit so here are the two classes I split.
public class Tab3 extends JPanel {
JPanel Annex = new JPanel();
//A Bunch of Labels and Buttons
.
.
.
public Tab3(){
//ActionListeners for the Buttons
this.setLayout(new BorderLayout());
this.add(Annex,BorderLayout.WEST);
this.add(Bsp,BorderLayout.EAST);
}}
All the GridBagLayout is in the following class:
public class Tab3Layout extends Tab3{
public Tab3Layout(){
Annex.setLayout(new GridBagLayout());
GridBagConstraints co1 = new GridBagConstraints();
co1.gridx = 0;
co1.gridy = 0;
co1.anchor = GridBagConstraints.FIRST_LINE_START;
co1.weighty = 1.0;
Annex.add(Annex1, co1);
//and so on...
}}
Now my question is, how do I get this to work? Right now if I compile, Tab3 is just empty. If everything is in one class it works exactly how I want, but the code is just much too long. Seems to me like I'm missing a line in the Tab3 class, but even after hours of tinkering and searching I have no idea how to solve this. Everything I tried just produced more errors.

The problem is in iheritance. Tab3Layout has its own Annex JPanel (inherited from Tab3), which it is modifying and adding components to, while Tab3 class is inserting its Annex, which is initialized via new JPanel() and you do nothing else with it. Tab3Layout class never even touches Annex panel you intialize and add in Tab3 .
public class Tab3 extends JPanel {
JPanel Annex = new JPanel(); // <----- this, an empty JPanel
//A Bunch of Labels and Buttons
public Tab3(){
//ActionListeners for the Buttons
this.setLayout(new BorderLayout());
this.add(Annex,BorderLayout.WEST); // <----- is inserted here
this.add(Bsp,BorderLayout.EAST);
}}
You will get an error if you delete new JPanel(), which will illustrate that both classes are doing work on different objects, which just happen to be named the same. You need to pass all components/panels you want to appear in Tab3 to Tab3Layout to modify, then you can retrieve them later with getters. Another way would be to create AnnexPanel class, which itself would be extending JPanel class. It would set its own layout, components etc. and be able to be added directly. Following Single Responsibility Principle would be best, if your classes grow in size. If it's 200+ lines of code, you should consider refactoring it. If you will allow your class to grow like 3000+ lines of code, you will have a bad time. Try to forsee where you can create new class/method in early stages of development. See KISS principle .
Well..I would split those in different way.
My Tab3Layout class. Annex panel is injected via constructor, you can set a setter for that, but remember to not call createAnnex() before injection. Anyway, compiler will make you remember.
public final class Tab3Layout {
private JPanel Annex;
JPanel Annex1; //just to avoid compiler error
private GridBagLayout gridBagLayout;
private GridBagConstraints co1;
public Tab3Layout(JPanel Annex) {
this.Annex = Annex;
this.gridBagLayout = new GridBagLayout();
this.co1 = new GridBagConstraints();
}
public void createAnnex() {
this.Annex.setLayout(gridBagLayout);
this.co1.gridx = 0;
this.co1.gridy = 0;
this.co1.anchor = GridBagConstraints.FIRST_LINE_START;
this.co1.weighty = 1.0;
this.Annex.add(Annex1, co1);
}
public JPanel getAnnex() {
return this.Annex;
}
}
And then the Tab3 class:
public class Tab3 extends JPanel {
JPanel Annex;
Tab3Layout tab3Layout;
public Tab3() {
super();
this.Annex = new JPanel();
this.tab3Layout = new Tab3Layout(Annex);
this.tab3Layout.createAnnex();
this.setLayout(new BorderLayout());
this.add(tab3Layout.getAnnex(), BorderLayout.WEST);
this.add(new JPanel(), BorderLayout.EAST);
}
}
Look at my GridBagManager repo, it can give you an idea how to set layout with another class.
You can also extend Tab3Layout with JPanel. And remember to set anchor and fill with GridBagConstraints.
And Java naming convention.
JPanel Annex = new JPanel();
GridBagConstraints co1 = new GridBagConstraints();
to
JPanel annexPanel = new JPanel();
GridBagConstraints gridBagConstraints = new GridBagConstraints();
Personally I use gbc for GridBagConstraints object, as you will see in my repo I mentioned above.
Edit:
I think you should split your implementation into couple of smaller classes. That would be professional aproach. Refactor your code. For starters you can make every panel its own class extending JPanel (like i suggested with AnnexPanel class).
Edit2: createAnnex() can return JPanel type, reducing your boilerplate code, your call then would be as follows:
this.add(Tab3Layout.createAnnex(), co1);
instead of
Tab3Layout.createAnnex();
this.add(Tab3Layout.getAnnex(), co1);
Maybe even take createAnnex() to constructor (assuming class extends JPanel) if it's a singleton.

JLabels not showing up

I am trying to figure why I can't see my labels like when I try to put 2 labels into 1 panel they dissapear, the only way I can seem to get it to work is if I add everything to JFrame with no type of hierarchy.
import javax.swing.*;
import java.awt.*;
public class GUI extends JFrame {
/**
*
*/
private static final long serialVersionUID = 1L;
static JRadioButton tirebg1 = new JRadioButton();
static JRadioButton tirebg2 = new JRadioButton();
static JRadioButton tirebg3 = new JRadioButton();
static ButtonGroup tirebg = new ButtonGroup();
public static void main(String[] args) {
Car cspeed = new Car();
int carspeed = cspeed.getSpeed();
Motorcycle mspeed = new Motorcycle();
int motospeed = mspeed.getSpeed();
Truck tspeed = new Truck();
int truckSpeed = tspeed.getSpeed();
JRadioButton wide = new JRadioButton();
JLabel tbuttons = new JLabel();
JPanel topPane = new JPanel();
tirebg.add(tirebg1);
tirebg.add(tirebg2);
tirebg.add(tirebg3);
JFrame GUIframe = new JFrame();
JLabel label1 = new JLabel();
label1.setLayout(new FlowLayout());
JLabel tireLabel = new JLabel();
String[] names = new String[5];
names[0] = "Car";
names[1] = "Truck";
names[2] = "Motorcycle";
String[] hello = new String[5];
GUIframe.setSize(500, 500);
GUIframe.setDefaultCloseOperation(EXIT_ON_CLOSE);
JList list = new JList(names);
list.setBorder(BorderFactory.createRaisedSoftBevelBorder());
label1.add(list);
tireLabel.add(tirebg1);
tireLabel.add(tirebg2);
tireLabel.add(tirebg3);
topPane.add(tbuttons);
topPane.add(tireLabel);
topPane.setLayout(new FlowLayout());
label1.setBackground(Color.cyan);
GUIframe.add(topPane);
GUIframe.validate();
GUIframe.setBackground(Color.GREEN);
GUIframe.setVisible(true);
}
}

Since you posted a lot of code and I'm not sure what were you trying to achieve, I modified your code adding 3 JLabels at the topPane. And 3 JRadioButtons (I didn't add the ButtonGroup) below on a second JPanel, I commented how to make them appear on a vertical and horizontal align.
Something you should take into account is:
Don't extend and create objects from JFrame (One or the other, not both, I recommend you to create objects).
You were giving your JPanel a Layout after adding components to it, it should be done before.
From the above point, you were also giving your Layout to your JLabel not your JPanel.
You were adding a JList into a JLabel.
You missed to have a class constructor too.
Don't have multiple JFrames for more see The use of multiple JFrames, Good / Bad practice
Next time post a code which has no dependencies such as your Truck, Car and Motorcycle classes (i.e. a Runnable example). And use plain text instead so we can copy-paste the code and see the issue. Also try posting images (or the link and we can edit to add it).
Now, the outpus of my own program are:
And it was done with the following code.
import javax.swing.*;
import java.awt.*;
public class GUIExample {
JFrame frame;
JLabel label1, label2, label3;
JPanel topPane, radioPane;
JRadioButton radio1, radio2, radio3;
public static void main(String[] args) {
new GUIExample();
}
GUIExample () {
frame = new JFrame();
topPane = new JPanel();
radioPane = new JPanel();
topPane.setLayout(new FlowLayout());
// radioPane.setLayout(new BoxLayout(radioPane, BoxLayout.PAGE_AXIS)); //Vertical align
radioPane.setLayout(new FlowLayout()); //Horizontal align
label1 = new JLabel("Car");
label2 = new JLabel("Motorcycle");
label3 = new JLabel("Truck");
radio1 = new JRadioButton("Radio1");
radio2 = new JRadioButton("Radio2");
radio3 = new JRadioButton("Radio3");
topPane.add(label1);
topPane.add(label2);
topPane.add(label3);
radioPane.add(radio1);
radioPane.add(radio2);
radioPane.add(radio3);
frame.add(topPane, BorderLayout.PAGE_START);
frame.add(radioPane, BorderLayout.CENTER);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
}

Your code has several issues, but the reason that you're not seeing the tireLabel or the tbuttons component is because you're using a JLabel. Understand that JLabel is not built to act as a container for other components. The key concept is that it calculates its preferred size based on the text it holds and/or the icon it holds and (and this is key) not on the sizes or preferred sizes of any components it might hold.
The solution is to not use JLabel for a purpose it wasn't intended for but rather to use a JPanel which does adjust its own preferred size depending on the sizes of its held components and its layouts.
Other unrelated issues:
Your program extends JFrame but never uses itself as a JFrame, something that will confuse anyone who reads your code. If you're not going to use the instance of the class as a JFrame, then don't extend the class.
Your program isn't an OOP-compliant program, one with instance fields, public methods, and such, but rather is little more than one large static main method, and this will result in a large God-method, one with too much responsibility, and one that is very difficult to debug and to maintain. Don't throw out the OOP baby with the bath water -- Create Swing GUI's in a well-behaved OOP-compliant way.
You're trying to set background colors to components that are not opaque (a JLabel), to components that are never added to the GUI (label1), or are not fully displayed (the JFrame).
You're using FlowLayout an awful lot, and in places where other layouts would probably serve you better. It's as if it's the only layout that you know how to use, and so you use it. Try branching out and using other layouts including GridLayout for your JRadioButton container and perhaps BorderLayout for the main container (JPanel).

Several similar panels GUI Java

I'm creating GUI and I don't know how to resolve my problem. What I'd like to do is to create several panels from PanelClass like i did in Main.
I don't know how:
Name buttons in my Panels and gave them some functionality (Like i was trying with button b1)
Add to panel3 additional labels, and buttons.
My main class
public class Main {
JFrame f;
PanelClass panel1, panel2, panel3;
JButton b1, b2;
public Main() {
b1 = new JButton("asasa");
f = new JFrame();
f.setSize(300, 300);
f.setLayout(new GridBagLayout());
f.setVisible(true);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
panel1 = new PanelClass(b1, b2, panel1);
panel2 = new PanelClass(b1, b2, panel2);
panel3 = new PanelClass(b1, b2, panel3);
f.add(panel1);
f.add(panel2);
f.add(panel3);
}
public static void main(String[] args) {
Main m = new Main();
}
}
My Panel class
public class PanelClass extends JPanel {
public PanelClass(JButton btn, JButton btn1, JPanel p) {
super();
p = new JPanel(new GridBagLayout());
btn = new JButton();
btn1 = new JButton();
GridBagConstraints c = new GridBagConstraints();
c.gridx = 0;
c.gridy = 0;
p.add(btn, c);
c.gridx = 0;
c.gridy = 1;
p.add(btn1, c);
add(p);
}
}

A component can only exist in one visible container at a time (unless it is being used as a flyweight renderer). So putting the same buttons into 3 panels will not work.
The code passes a button(s) in the constructor of PanelClass which is(are) ignored. Instead 2 new button instances are created. Just assign the passed buttons to the ..I was going to say 'class level attributes' when I noted they were not. Entirely remove
btn = new JButton(); and the text passed in the button constructor will appear.
For events, see How to Write an Action Listener.

Try to read the official Swing tutorial. It explains how to add panels, labels, etc.
To edit label names you could use setText(String name) method. To add functionalities to buttons you must implement a listener in each one. Add labels like you do in other panels, I don't see the problem.

To add "events" like click and mouse hovers etc - you must implement the correct "Listener" for the Widget. Go through any good tutorial on Swing and it will tell you everything about it. Widgets on screen are regular objects as well, so they can be added to "Collections", iterated and played around with, like regular objects. Take note of THREAD complexities and warning 'Cross-Thread invocation is Injurious To Your Program'.

Java Swing interface issue

here's my problems : I tried to create a simple interface from where I can click on several buttons that call differents functions, and show the result (which always is text) in a jlabel.I tried to have 2 separates parts (north/south or east/west) The first area would contain a gridlayout or flowlayout of all my buttons and the 2nd area would show the text result.
Here are my declarations :
private static JButton b0 = new JButton("Creer Zone");
private static JButton b1 = new JButton("1");
private static JButton b2 = new JButton("2");
...
private static JButton b11= new JButton("11");
private static JButton b12 = new JButton("12");
private static JButton b14 = new JButton("Help");
private static JFrame windows = new JFrame();
private static JPanel container = new JPanel();
private static JLabel res = new JLabel();
and here is how i added them to the JFrame (which is really awfull to see) :
container.add(b0);
container.add(b1);
container.add(b2);
...
container.add(b12);
container.add(b14);
container.add(res);
windows.setSize(450,500);
windows.setContentPane(container);
windows.setLocation(150 , 150);
windows.setVisible(true);
I've tried to declare my jpanel with a gridlayout, a borderlayout and change the location (N S E W) and a flowlayout, i always ended up with the jlabel disapearing (which is bad because this jlabel show the result of my functions)
Any one have a simple way to help me overcome this ? Thanks a lot for any time you take

nicely explained on http://docs.oracle.com/javase/tutorial/uiswing/layout/gridbag.html

Another possible solution for your future endeavors is to look into WindowsBuilder. It basically simplifies your layout design by allowing you to just simply drag and drop your elements (Jframe, JtextField, etc) and then in the background WindowsBuilder will write the code for you. Mind you the only thing that you will have to really add/change is the naming conventions of the buttons and of course the eventHandlers, but honestly those are something that any designer would want to control... Hopefully this helps you!
https://developers.google.com/java-dev-tools/wbpro/