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JTabbedPane Malfunctioning

I have a problem with my code. I am trying to get into user interfaces in Java, and have started using JOptionPane. At the moment, I'm experimenting with JTabbedPane, but I have a problem with it. My problem is the following: when I try to run the code, so that a panel with one tab appears reading 'You are using the program "CarDealership".', nothing happens. I don't know what's the problem, but my terminal reads the following when I compile and run my program...:
Terminal...: TerminalOutput
My code...: ProgramCode
I'm coding in Visual Studio Code, and, as you can tell by reviewing the code, I am from México. I translated the variables used in the program in a comment. Thank you for reading!
Code in text...:
/*
The name of the program translates to 'ProgCarDealership'.
Variables used...:
Example: 'Type/NameInSpanish/NameInEnglish'
- JTabbedPane/Pestañas/Tabs
- JLabel/Contenido/Content
- JPanel/Pestaña1/Tab1
*/
import javax.swing.*;
public class ProgLoteDeCarros extends JFrame
{
public VentanaPrincipal()
{
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setExtendedState(MAXIMIZED_BOTH);
setVisible(true);
setTitle("Programa Lote de Carros");
JTabbedPane Pestañas = new JTabbedPane();
JPanel Pestaña1 = new JPanel();
JLabel Contenido = new JLabel ("Estas usando el programa 'Lote de Carros'.");
Pestaña1.add(Contenido);
Pestañas.addTab("Información", Pestaña1);
getContentPane().add(Pestañas);
}
public static void main (String [] Yoshi)
{
ProgLoteDeCarros VentanaPrincipal = new ProgLoteDeCarros();
}

Nothing happens when I try to apply an ActionListener to a JButton to change the content of the JLabel

I need a way to create an ActionListener that when a JButton is pressed, it updates the content of 7 different JLabels to display the information in the form of text.
The data is retrieved from methods called from an external JAR file. The methods return ArrayList. I attempted to convert the ArrayList into a String, and tried to change the JLabel content with setText().
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import api.anAPI.THEAPINAME;
public class Controller implements ActionListener {
private MainGUI maingui;
private SubPanel subpanel;
private static THEAPINAME anAPI =new THEAPINAME("XyP0D75oRCGrLE78","x47ka5jmOGaJ2zvw");
static ArrayList<String> nameList =new ArrayList<String>();
private String names;
public Controller(MainGUI maingui,SubPanel subpanel){
this.maingui = maingui;
this.SubPanel = subpanel;
MainGUI.getSearchBtn().addActionListener(this);
nameList.addAll(anAPI.getNames());
for (String s: nameList){
names+= s+"\t";
}
}
public void actionPerformed(ActionEvent e) {
SubPanel.label1.setText(names);
//6 more Labels.
}
}
An additional, because I have 7 JLabels, would I need to do 7 getLabel methods? Or is there a way to get them all with just 1 method.
I am not entirely sure what I am doing incorrectly, it could be that the getMethods I used returned the wrong widget in question as the code for the GUI was not done by me but by a teammate and he had done a really poor job of making it clear for us.
UPDATE:
Fixed up the GUI to make it clearer, so I think that is no longer the problem. Now I think the problem might be that I did not convert the contents of the ArrayList into a String in the way I thought.
The desired function of the code is when the JButton is clicked on, the JLabels in question are all updated to their relevant data.
addController method
public void addController(Controller controller){
control = controller;
jb1.addActionListener(control);
}

You didn't really describe what the problem is of your current code.
You can add a method say getLabels() in SubPanel class to return all of its labels, or you can add a method setLabelText(String text) to set text for all of its labels by extending or directly modifying SubPanel class.
UPDATE
You have several very confusing parts in your code.
In your constructor, it should be this.subpanel = subpanel and then it should be maingui.getSearchBtn().addActionListener(this), also in method actionPerformed it should be subpanel.label1.setText(names). These might not be your problems though since you didn't say it's the code you're actually running.
Looks like that you haven't created any instance of class Controller thus the code in it never gets executed.
You need to have some code outside of you Controller class like this:
MainGUI maingui;
SubPanel subpanel;
// they're somehow initialized
Controller controller = new Controller(maingui, subpanel);

how to use text fields in java

I just have a very basic question about how to use textfields in Java. It's very simple, but the tutorials and other questions I've been looking for haven't been helpful, and I'm hoping that someone can explain things a little more clearly for me.
Right now I have the following code that I just sort of slapped together for the sake of example:
import javax.swing*;
public class testText {
public static void main(String[] args){
JFrame frame = new JFrame();
JTextField text = new JTextField();
frame.add(text);
frame.setVisible(true);
System.out.println(text.getText());
}
}
All I'm trying to do, is print what the user types into the text field in the console. But nothing happens when I type into the text field.
Now,based on the research I've done, I think the problem is that I'm not using an actionListener. The thing is, I really don't understand how those work, and I'm hoping someone can clarify for me.
I've been using this tutorial to try and figure things out, and particularly the TextDemo example they have near the top. I'm still kind of at a loss though, and I can't seem to find any way to use the actionlistener interface without breaking the program. If someone could either just explain simply and directly how to use the actionlistener to pull a string from a text field and then use it, or else point me to somewhere else where I can FIND a simple straightforward explanation, I would immensely appreciate it. I've been beating my head against this for five hours now with absolutely nothing to show for it, so I apologize for asking such a basic question but I'm at a loss.

An action listener will be called when an enter key is pressed while typing in the field. From the JTextfield Javadoc :
How the text field consumes VK_ENTER events depends on whether the
text field has any action listeners. If so, then VK_ENTER results in
the listeners getting an ActionEvent, and the VK_ENTER event is
consumed.
Here is your example modified to work with an action listener :
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JTextField;
public class testText {
public static void main(String[] args){
JFrame frame = new JFrame();
final JTextField text = new JTextField();
frame.add(text);
frame.setVisible(true);
text.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println(text.getText());
}
});
}
}
And here is an object oriented complete example not relying only on a static main method.

Contentpanes not working in java

I can reply as soon as tomorrow morning (I'm really tired)
source of how I did this:
http://docs.oracle.com/javase/tutorial/uiswing/components/frame.html
This line of code is giving me errors:
win1.getContentPane().add(emptyLabel, BorderLayout.CENTER);
The part I'm having issues with is:
emptyLabel
It throws an error and it says to change to win1, which doesn't show the error but throws it
Full Class:
package examplepackage;
//imports
import java.awt.BorderLayout;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import examplepackage.location.GetFilepath;
public class Starter {
public static void main(String[] args){
GetFilepath FP = new GetFilepath();
JFrame win1 = new JFrame("examplewindow");
win1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
win1.getContentPane().add(emptyLabel, BorderLayout.CENTER);
win1.pack();
win1.setSize(600, 800);
win1.setVisible(true);
win1.setLocationRelativeTo(win1);
win1.setIconImage(new ImageIcon(FP + "\\window\\Main").getImage());
}
}

So, based on you example, removing the references to GetFilePath, as I don't have access to that source, when I compile your code I get...
error: cannot find symbol
win1.getContentPane().add(emptyLabel, BorderLayout.CENTER);
^
symbol: variable emptyLabel
location: class Starter
Which basically means that emptyLabel is not defined. It's possible that your IDE is looking for a matching value that could be passed to the method parameter, again, based on you code, that leaves win1, which obviously isn't going to work (you can't add something to itself or a Window based component to a Container)
What you need to to is define and create an instance of some component, such as a JLabel, for example...
JLabel emptyLabel = new JLabel();
win1.getContentPane().add(emptyLabel, BorderLayout.CENTER);
I'd also suggest you have a read through Initial Thread and make sure you are initialising your UI's within the context of the Event Dispatching Thread

emmptyLabel is never initialized

Different windows with the same code?

This is the "main" class (doesn't contain the main method)
import javax.swing.*;
import java.awt.*;
//import java.lang.Object;
//import java.awt.event.ActionListener;
//import java.awt.event.;
public class Program {
public JFrame frame;
public JPanel header;
public JPanel text;
public JPanel body;
public JTextField input;
public JButton agregar;
public List listA;
public List listB;
public Program(String title) {
frame = new JFrame(title);
frame.setSize(500,600);
frame.setResizable(false);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(null);
header = new JPanel();
header.setBackground(new Color(255,204,50));
header.setBounds(0,0,500,100);
text = new JPanel();
text.setBackground(new Color(255,204,100));
text.setBounds(0,100,500,50);
text.setLayout(null);
//Inicializando la "entrada"
input = new JTextField(20);
input.setBounds(50,13,300,25);
text.add(input);
agregar = new JButton();
agregar.setBounds(360,12,80,25);
agregar.setText("Agregar");
text.add(agregar);
//Listo
body = new JPanel();
body.setBackground(new Color(255,204,150));
body.setBounds(0,150,500,450);
//Lo que está dentro del body
listA = new List(20);
body.add(listA);
listB = new List(20);
body.add(listB);
//Listo
//Añadir todos los paneles al frame principal
frame.add(header);
frame.add(text);
frame.add(body);
}
}
And this is the MAIN class (This one contains the main method):
public class Main {
public static void main(String[] args) {
new Program("Ordenamiento Recursivo");
}
}
Each time I run the application, the UI components are presented differently, please see attached screen shot.
Well, thanks to everyone who responded the post, I finished the program and I'm very happy with the final result, here it is:
In case anyone wants to take a look at the code, here it is: Link

Problems:
You're call setVisible(true) on your JFrame before adding components and this will lead to unreliable drawing of your program's graphics and is why you are seeing different results. Don't do this, but rather call it after you've added all to the top-level Window.
As the others are saying, read up and learn to use the layout managers.

Different windows with the same code?
I think that is very simple and possible by implements CardLayout
I'd suggest don't opening a new Top-Level Container, only if is there really important reason then use JDialog or JOptionPane

Be sure to construct the GUI on the EDT. Not doing so can cause unpredictable results.
Call pack() after the components are added using layouts and then call setVisible(true).

You will need a layout manager for your form so setting the layout manager to null is not the thing to do.
Work in progress here ... https://gist.github.com/2510570
Couple of changes. Not quite finished yet, but check out the following
Have Program extend a JFrame.
Have set a layout manager.
Update
Finally I knocked this up in IntelliJ's form designer.
https://gist.github.com/2512197
Where you want to attach behaviour to the buttons search through the code for the comments that ask you to add code. Although I did this in the InteliJ Ultimate (this one that costs money) I think that no-cost free to download Community Edition UI designer also paints Swings GUIs. Very quick and easy. Netbeans also has a good GUI painter.
The Swing Tutorial on oracle.com is worth reviewing also.