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How do I move a table to the left if it is in a JPanel?

I am trying to move a table to the left side of a JPanel which is also inside a Window
What I get is this:
What I want is this:
I tried using .setBounds method but it does not work. Does anyone know what to do?
This is my code:
package Modulos;
import paneles.*;
import javax.swing.*;
public class ModuloAdmin extends JFrame {
public ModuloAdmin(){
//Crear tabla
String[][] datosprueba = {
{"001","Carlitos", "Casa","51202011"},
{"001","Carlitos", "Casa","51202011"}
};
String[] TituloColumna = {"Código", "Nombre", "Dirección", "Teléfono"};
JTable TablaSucursales = new JTable(datosprueba,TituloColumna);
//Contenido de las pestañas
JPanel PanelSucursales = new JPanel();
PanelSucursales.add(TablaSucursales);
PanelSucursales.add(new JScrollPane(TablaSucursales));
JPanel PanelProductos = new JPanel();
PanelProductos.add(new JLabel("Panel productos"));
JPanel PanelClientes = new JPanel();
PanelClientes.add(new JLabel("Panel Clientes"));
JPanel PanelVendedores = new JPanel();
PanelVendedores.add(new JLabel("Panel Vendedores"));
//CREACION DE PESTAÑAS
JTabbedPane Pestanias = new JTabbedPane();
Pestanias.setBounds(20,80,700,700);
Pestanias.add("Sucursales",PanelSucursales);
Pestanias.add("Productos",PanelProductos);
Pestanias.add("Clientes", PanelClientes);
Pestanias.add("Vendedores",PanelVendedores);
//vENTANA MODULO DE ADMIN
JFrame VentanaModuloAdmin = new JFrame();
VentanaModuloAdmin.add(Pestanias);
VentanaModuloAdmin.setLayout(null);
VentanaModuloAdmin.setSize(800,850);
VentanaModuloAdmin.setLocationRelativeTo(null);
VentanaModuloAdmin.setTitle("Módulo de administrador");
VentanaModuloAdmin.setVisible(true);
VentanaModuloAdmin.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
}
}

Use appropriate layout mangers and container management
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.border.EmptyBorder;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame();
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JTable table;
public TestPane() {
setBorder(new EmptyBorder(16, 16, 16, 16));
setLayout(new GridLayout(0, 2));
add(new JScrollPane(table));
add(createButtonPane());
}
protected JPanel createButtonPane() {
JPanel panel = new JPanel(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.ipadx = 16;
gbc.ipady = 16;
gbc.fill = gbc.HORIZONTAL;
gbc.gridx = 0;
gbc.gridy = 0;
panel.add(new JButton("Clear"), gbc);
gbc.gridx = 1;
panel.add(new JButton("Carga Masiva"), gbc);
gbc.gridy++;
gbc.gridx = 0;
panel.add(new JButton("Actualizar"), gbc);
gbc.gridx = 1;
panel.add(new JButton("Eliminar"), gbc);
gbc.gridy++;
gbc.gridx = 0;
gbc.gridwidth = 2;
gbc.anchor = GridBagConstraints.NORTH;
gbc.weighty = 1;
panel.add(new JButton("Exportar Listado a PDF"), gbc);
return panel;
}
}
}
Seriously, layout managers solve one of the most difficult issues facing UI developers - the variable nature of the output (screen resolutions, font metrics, accessibility modifiers, a whole bunch of different stuff which changes how layouts need to be calculated).
They might seem difficult to start with, but once you get use to using them and learn how to make use of "compound layouts", which is demonstrated above, it will help you make better UIs more quickly

Java JScrollpane not visible

I'm trying to display a series of buttons in a JScrollpane. Reading around, I managed to exit with this code, but nothing is displayed. I do not understand a possible mistake. Thank you for help
As suggested I made some changes, I edited but not works
EDITED
or I'm stupid, or here is some other problem. Here is my complete code with the output image
public class Main extends javax.swing.JFrame {
private final JPanel gridPanel;
public Main() {
initComponents();
// EXISTING PANEL
gridPanel = new JPanel();
JScrollPane scrollPane = new JScrollPane(gridPanel);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
JPanel borderLayoutPanel = new JPanel(new BorderLayout());
borderLayoutPanel.add(scrollPane, BorderLayout.CENTER);
this.Avvio();
}
private void Avvio() {
JPanel pane = new JPanel(new GridBagLayout());
pane.setBorder(BorderFactory.createLineBorder(Color.BLUE));
pane.setLayout(new GridBagLayout());
for (int i = 0; i < 10; i++) {
JButton button;
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.HORIZONTAL;
c.anchor = GridBagConstraints.PAGE_START;
button = new JButton("Button 1");
c.weightx = 0.5;
c.gridx = 0;
c.gridy = i;
pane.add(button, c);
button = new JButton("Button 2");
c.gridx = 1;
c.gridy = i;
pane.add(button, c);
button = new JButton("Button 3");
c.gridx = 2;
c.gridy = i;
pane.add(button, c);
}
gridPanel.add(pane);
gridPanel.revalidate();
gridPanel.repaint();
}
}

Alright, from your comments in another answer:
No problem for compile , simply the Jpanel is empty. The buttons does not appear.
After calling this.Avvio(); you must call:
this.add(scrollPane);
this.pack();
This will produce the following outputs (before and after resizing it):
But there's still no JScrollPanel
This at least solves the first problem, however you have more errors in your code, some of which have already been commented in other answers:
You're extending JFrame, this isn't needed as you can create a JFrame instance / object and use it later. You're never changing the JFrame's behavior and that's why it's not needed to extend it. See Extends JFrame vs. creating it inside the program for more information about this.
You're not calling pack() nor setSize(...) this creates a tiny window, which you need to manually resize. Call pack() recommended before making your JFrame visible. (As suggested at the beginning of this answer).
You're calling .invokeLater() method twice. You need to call it just once, I prefer this way:
SwingUtilities.invokeLater(() -> new Main()); //Note there is no call to .setVisible(true); as per point #1. It should go later in the program like: frame.setVisible(true);
You're calling gridPanel.revalidate(); and gridPanel.repaint() while it doesn't affect your program, it's not needed as your GUI is still not visible, and thus those calls have no effect on your program, you can safely remove them.
You're creating a new GridBagConstraints object on each iteration of the for loop, you can just change its properties inside it and declaring it outside the for loop, which will make your program better.
After following the above recommendations, you can end up with a code like this one:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
public class Main {
private final JPanel gridPanel;
private JFrame frame;
public Main() {
// EXISTING PANEL
gridPanel = new JPanel();
JScrollPane scrollPane = new JScrollPane(gridPanel);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
JPanel borderLayoutPanel = new JPanel(new BorderLayout());
borderLayoutPanel.add(scrollPane, BorderLayout.CENTER);
this.Avvio();
frame.add(scrollPane);
frame.pack();
frame.setVisible(true);
}
private void Avvio() {
JPanel pane = new JPanel(new GridBagLayout());
pane.setBorder(BorderFactory.createLineBorder(Color.BLUE));
pane.setLayout(new GridBagLayout());
for (int i = 0; i < 10; i++) {
JButton button;
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.HORIZONTAL;
c.anchor = GridBagConstraints.PAGE_START;
button = new JButton("Button 1");
c.weightx = 0.5;
c.gridx = 0;
c.gridy = i;
pane.add(button, c);
button = new JButton("Button 2");
c.gridx = 1;
c.gridy = i;
pane.add(button, c);
button = new JButton("Button 3");
c.gridx = 2;
c.gridy = i;
pane.add(button, c);
}
gridPanel.add(pane);
}
public static void main(String args[]) {
/* Create and display the form */
SwingUtilities.invokeLater(() -> {
new Main();
});
}
}
Which still produces this output:
BUT... We still can improve it a little more!
We may have two nested for loops, for the GridBagConstraints properties as well as the generation of the buttons:
import java.awt.BorderLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
public class ScrollablePaneWithButtons {
private static final int ROWS = 10;
private static final int COLS = 3;
private JFrame frame;
private JPanel pane;
private JButton[][] buttons;
private GridBagConstraints gbc;
private JScrollPane scroll;
private JButton[] menuButtons;
private JPanel menuPane;
public static void main(String[] args) {
SwingUtilities.invokeLater(new ScrollablePaneWithButtons()::createAndShowGui);
}
private void createAndShowGui() {
frame = new JFrame(this.getClass().getSimpleName());
pane = new JPanel();
pane.setLayout(new GridBagLayout());
menuPane = new JPanel();
menuPane.setLayout(new GridLayout(1, 3));
buttons = new JButton[ROWS][COLS];
menuButtons = new JButton[] {new JButton("Edit"), new JButton("Delete"), new JButton("Sort Fields")};
gbc = new GridBagConstraints();
gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.anchor = GridBagConstraints.PAGE_START;
gbc.weightx = 0.5;
for (int i = 0; i < ROWS; i++) {
for (int j = 0; j < COLS; j++) {
buttons[i][j] = new JButton("Button " + (j + 1));
gbc.gridx = j;
gbc.gridy = i;
pane.add(buttons[i][j], gbc);
}
}
scroll = new JScrollPane(pane, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
for (JButton b : menuButtons) {
menuPane.add(b);
}
frame.add(scroll);
frame.add(menuPane, BorderLayout.SOUTH);
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
And this example is (in my opinion) easier to read and follow up. And this is the output the above code is generating:
You can still choose which code to use, either doing the modifications at the first part of this answer, the second one following the recommendations above or the last one which is shorter.

Problems noted:
Avvio - the pane layout was reset during each loop. Set it once before the loop.
Avvio - the pane was added to the grid pane in each loop. Add it once after the loop.
Avvio - the constraints place the buttons in the same grid locations. With the previous two issues fixed, only the last three buttons placed appear.
I'm assuming you want three buttons in a row, so I changed the loop to use the counter as a row counter. The code below will create ten rows of three buttons.
What appears:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.WindowConstants;
public class Main extends javax.swing.JFrame {
private JPanel gridPanel;
public Main() {
this.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
this.setSize(600,400);
//EXISTING PANEL
gridPanel = new JPanel();
JScrollPane scrollPane = new JScrollPane(gridPanel);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
JPanel borderLayoutPanel = new JPanel(new BorderLayout());
borderLayoutPanel.add(scrollPane, BorderLayout.CENTER);
this.Avvio();
this.add(borderLayoutPanel, BorderLayout.CENTER);
this.setVisible(true);
}
private void Avvio() {
JPanel pane = new JPanel(new GridBagLayout());
pane.setBorder(BorderFactory.createLineBorder(Color.BLUE));
pane.setLayout(new GridBagLayout());
for (int i = 0; i < 10; i++) {
JButton button;
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.HORIZONTAL;
c.anchor = GridBagConstraints.PAGE_START;
button = new JButton("Button 1");
c.weightx = 0.5;
c.gridx = 0;
c.gridy = i;
pane.add(button, c);
button = new JButton("Button 2");
c.gridx = 1;
c.gridy = i;
pane.add(button, c);
button = new JButton("Button 3");
c.gridx = 2;
c.gridy = i;
pane.add(button, c);
}
gridPanel.add(pane);
gridPanel.revalidate();
gridPanel.repaint();
}
public static void main(String args[]) {
new Main();
}
}

There are several things to do to make it work:
Add a main method
This main method is the entry point. This makes sure the swing-code runs in the AWT-thread. This is what the SwingUtilities.invokeLater is for
Instantiate, pack and display the frame. The size setting is only for experimenting with the scrollpane
Declare the gridPanel as an instance variable
wrap the gridPanel with the scrollPane
Optionally, wrap the scrollPane with the borderLayoutPanel
Invoke the Avvio method because this is the one that adds the buttons
Add the outmost element to the frame
Here is the fixed code:
public class MyFrame extends javax.swing.JFrame {
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
MyFrame frame = new MyFrame();
frame.pack();
frame.setSize(600, 300);
frame.setVisible(true);
});
}
private JPanel gridPanel;
public MyFrame() {
this.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
gridPanel = new JPanel(new GridLayout(0, 1));
JScrollPane scrollPane = new JScrollPane(gridPanel);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
JPanel borderLayoutPanel = new JPanel(new BorderLayout());
borderLayoutPanel.add(scrollPane, BorderLayout.CENTER);
this.Avvio();
this.add(borderLayoutPanel, BorderLayout.CENTER);
}
private void Avvio() {...}
}

I have simplified the program and removed all the mistakes
and bad practices. (Missing package, unnecessary panels, calling invokeLater() twice and others.)
Here is a working example:
package com.zetcode;
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class JavaScrollPaneEx extends JFrame {
public JavaScrollPaneEx() {
initUI();
}
private void initUI() {
JPanel panel = new JPanel(new BorderLayout());
JPanel buttonPanel = createButtonPanel();
JScrollPane scrollPane = new JScrollPane(buttonPanel);
panel.add(scrollPane, BorderLayout.CENTER);
add(panel);
setTitle("Buttons in JScrollBar");
setSize(350, 250);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
private JPanel createButtonPanel() {
JPanel panel = new JPanel(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.HORIZONTAL;
c.anchor = GridBagConstraints.PAGE_START;
c.insets = new Insets(5, 5, 5, 5);
for (int i = 0, j = 0; i < 5; i++) {
JButton btn = new JButton("Button " + (j + 1));
c.weightx = 0.5;
c.gridx = i;
c.gridy = 0;
panel.add(btn, c);
btn = new JButton("Button " + (j + 2));
c.gridx = i;
c.gridy = 1;
panel.add(btn, c);
btn = new JButton("Button " + (j + 3));
c.gridx = i;
c.gridy = 2;
panel.add(btn, c);
j += 3;
}
return panel;
}
public static void main(String args[]) {
EventQueue.invokeLater(() -> {
JavaScrollPaneEx ex = new JavaScrollPaneEx();
ex.setVisible(true);
});
}
}
And this is the screenshot.
And since I consider GridBagLayout to be a very bad
layout manager, I have created a similar example with MigLayout
manager.
We need the following Maven dependency for this example:
<dependency>
<groupId>com.miglayout</groupId>
<artifactId>miglayout-swing</artifactId>
<version>5.0</version>
</dependency>
The source:
package com.zetcode;
import java.awt.BorderLayout;
import java.awt.EventQueue;
import javax.swing.JButton;
import javax.swing.JFrame;
import static javax.swing.JFrame.EXIT_ON_CLOSE;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import net.miginfocom.swing.MigLayout;
public class JavaScrollPaneEx2 extends JFrame {
public JavaScrollPaneEx2() {
initUI();
}
private void initUI() {
JPanel panel = new JPanel(new BorderLayout());
JPanel buttonPanel = createButtonPanel();
JScrollPane scrollPane = new JScrollPane(buttonPanel);
panel.add(scrollPane, BorderLayout.CENTER);
add(panel);
setTitle("Buttons in JScrollBar");
setSize(350, 250);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
private JPanel createButtonPanel() {
JPanel panel = new JPanel(new MigLayout());
for (int i = 0, j = 0; i < 5; i++) {
JButton btn1 = new JButton("Button " + (j + 1));
JButton btn2 = new JButton("Button " + (j + 2));
JButton btn3 = new JButton("Button " + (j + 3));
JButton btn4 = new JButton("Button " + (j + 4));
JButton btn5 = new JButton("Button " + (j + 5));
panel.add(btn1, "sgx");
panel.add(btn2, "sgx");
panel.add(btn3, "sgx");
panel.add(btn4, "sgx");
panel.add(btn5, "sgx, wrap");
j += 5;
}
return panel;
}
public static void main(String args[]) {
EventQueue.invokeLater(() -> {
JavaScrollPaneEx2 ex = new JavaScrollPaneEx2();
ex.setVisible(true);
});
}
}

GridBagLayout not working inside JPanel *Updated*

First post, and tried to research this as much as possible but finally gave up and decided to ask.
I am building a recipe book program, and on one page it has the list of recipes. When you select a recipe it will appear on the left side as labels. The issue is on my page I have two JPanels. One hosts the list of recipes, the other is labels for displaying the information. On the side that has the labels I cant get them to move, or alter or anything inside the JPanel.
I feel this has a simple solution but I am too inexperienced to see. Anyway thanks for the help in advance.
////Form Panel Class
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import javax.swing.BorderFactory;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class FormPanel extends JPanel {
private JScrollPane pane;
private JPanel pane2;
// viewing of information
private JLabel nameLabel1;
private JLabel nameLabel2;
private JLabel nameLabel3;
public FormPanel() {
nameLabel1 = new JLabel("Label1");
nameLabel2 = new JLabel("Recipe Name: ");
nameLabel3 = new JLabel("Tag Lines: ");
pane = new JScrollPane();
pane2 = new JPanel();
layoutComponents();
pane.setPreferredSize(new Dimension(200, 450));
pane2.setBorder(BorderFactory.createTitledBorder("Recipes"));
pane2.setPreferredSize(new Dimension(375, 450));
}
public void layoutComponents() {
setLayout(new GridBagLayout());
GridBagConstraints gc = new GridBagConstraints();
///////////////////////////////////////
// First Row
gc.gridy = 0;
gc.weightx = 1;
gc.weighty = 1;
gc.gridx = 1;
gc.anchor = GridBagConstraints.FIRST_LINE_START;
add(pane2, gc);
////////////////////////////////////////////
///////////////////////////////////////
// First Row
gc.gridy = 0;
gc.weightx = 2;
gc.weighty = 1;
gc.gridx = 1;
gc.anchor = GridBagConstraints.FIRST_LINE_END;
gc.insets = new Insets(5, 5, 5, 5);
add(pane, gc);
////////////////////////////////////////////
GridBagConstraints gc2 = new GridBagConstraints();
//
gc2.gridy = 0;
gc2.weightx = 1;
gc2.weighty = 1;
gc2.gridx = 0;
gc2.fill = GridBagConstraints.PAGE_START;
pane2.add(nameLabel2, gc2);
////////////////////////////////////////////
gc2.gridy = 1;
gc2.weightx = 1;
gc2.weighty = 1;
gc2.gridx = 0;
gc2.fill = GridBagConstraints.CENTER;
pane2.add(nameLabel3, gc2);
////////////////////////////////////////////
gc2.gridy = 2;
gc2.weightx = 1;
gc2.weighty = 1;
gc2.gridx = 0;
gc2.fill = GridBagConstraints.SOUTH;
pane2.add(nameLabel1, gc2);
}
}
//Mainframe Class
import java.awt.BorderLayout;
import java.awt.Dimension;
import javax.swing.JFrame;
import javax.swing.JTabbedPane;
public class Mainframe extends JFrame {
private FormPanel formPanel;
private JTabbedPane tabPane;
public Mainframe() {
super("My Digital Cookbook");
setLayout(new BorderLayout());
formPanel = new FormPanel();
tabPane = new JTabbedPane();
add(tabPane, BorderLayout.PAGE_START);
tabPane.addTab("New Recipe", formPanel);
setMinimumSize(new Dimension(500, 600));
setSize(600, 600);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
}
//Application Class
import javax.swing.SwingUtilities;
public class Application {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run(){
System.out.println(SwingUtilities.isEventDispatchThread());
new Mainframe();
}
});
}
}
The lower three labels might have wonkey weights and what not just due to trying to get them to move but they all just stay in a straight line near the top of the Jpanel.
Additionally I don't think I needed to re-declare my gridbagconstraints but I decided to try for debugging attempts.
**Update -I now have posted a much simpler version of my program with the error still existing. I apologize that I don't have it smaller due to lack of flexible skills.

Java Swing: JScrollPane containing JTextArea filled with text gets very small when moved to 2nd monitor

I have a Java Swing GUI that consists of some JScrollPanes containing JTextAreas that get filled with data so that the scrollbars appear. Once the scrollbars appear, when I move the window to my second monitor, the JScrollPane gets very small so that I can no longer see the text it contains.
Example:
Here is the window on my main monitor with the JScrollPane filled with text:
Here is the window after I filled it with text and moved it to the second monitor:
Here is a small example program that demonstrates the problem:
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;
public class Main extends JFrame {
public Main() {
Test theGui = new Test();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setResizable(true);
add(theGui);
pack();
setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new Main();
}
});
}
}
class Test extends JPanel {
private static final int PADDING = 3;
private JLabel label;
private JTextArea textarea;
private JScrollPane scrollpane;
private GridBagConstraints gbc;
public Test() {
super(new GridBagLayout());
label = new JLabel("Fill this text box with text so the scrollbars appear, then move the window to 2nd monitor:");
textarea = new JTextArea(10, 40);
scrollpane = new JScrollPane(textarea);
gbc = new GridBagConstraints();
gbc.gridheight = 1;
gbc.insets = new Insets(PADDING, PADDING, PADDING, PADDING);
gbc.anchor = GridBagConstraints.LINE_START;
gbc.fill = GridBagConstraints.BOTH;
gbc.gridwidth = 4;
gbc.gridx = 0;
gbc.gridy = 0;
add(label, gbc);
gbc.gridx = 0;
gbc.gridy = 1;
add(scrollpane, gbc);
}
}
Note that the JScrollPane only gets very small when moving to the other monitor when it is filled with text. If there is no text in it, it seems to stay the right size.
My question is, how can I prevent the JScrollPane from getting very small when I move the window to my second monitor?

GridBagLayout will revert to the components minimumSize property when the available space for the component is less then the components preferredSize.
You can override this by using the GridBagConstraints, weightx/weighty properties, for example.
gbc.gridx = 0;
gbc.gridy = 1;
gbc.weightx = 1;
gbc.weighty = 1;
add(scrollpane, gbc);

positionnig myJTextField beside JComboBox

I want to creat a palet with many JComboBox. like that :
for(int x=0; x<MAX; x++){
box[x] = new JComboBox(new String[]{"op1", "op2", "op3");
}
at the right of each JComboBox i want to create many JTextField. So, in my palet i will have some think like that:
myJComboBox1 myJTextField
anotherJTextField
anotherJTextField
myJComboBox2 myJTextField
anotherJTextField
anotherJTextField
...
How can i do that please ? I tried by setBounds and other layout like FlowLayout and GridLayout but without success.

GridBagLayout is the best solution. However, if you are new to Swing, it might be a bit over complicated. In that case:
Use GridLayout(0, 2) for the main panel.
Wrap the combobox in a Panel with a border layout and add it to north. Add it to the main panel.
Use another panel with GridLayout(0,1) add your text fields to it and add it to the main panel.
and loop...
Adding sample code:
package snippet;
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.GridLayout;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class BorderLayoutTest extends JFrame {
static private int MAX = 10 ;
public BorderLayoutTest() {
super(BorderLayoutTest.class.getName());
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
initComponents();
}
private void initComponents() {
setLayout(new GridLayout(0, 2));
for(int i = 0; i < MAX; i++) {
add(createComboPanel());
add(createPanelWithTextFields());
}
pack();
}
public Component createComboPanel() {
JPanel panel = new JPanel(new BorderLayout());
panel.add(new JComboBox<>(new String[] { "First Option", "Second Option", "Third Option" }), BorderLayout.NORTH);
return panel;
}
private Component createPanelWithTextFields() {
JPanel panel = new JPanel(new GridLayout(0, 1));
panel.add(new JTextField(30));
panel.add(new JTextField(30));
panel.add(new JTextField(30));
return panel;
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override public void run() {
new BorderLayoutTest().setVisible(true);
}
});
}
}

Take a look at GridBagLayout. You can use your window like a table.
myPanel.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
gbc.weightx = 1;
JLabel lbl = new JLabel("bla");
myPanel.add(lbl, gbc);
gbc = new GridBagConstraints();
gbc.gridx = 1;
gbc.gridy = 0;
gbc.weightx = 3;
JTextField tf = new JTextField();
myPanel.add(tf, gbc);
gbc = new GridBagConstraints();
gbc.gridx = 1;
gbc.gridy = 1;
gbc.weightx = 3;
JTextField othertf = new JTextField();
myPanel.add(othertf, gbc);
You can even set weights and so on for the GridBagConstraints. It is completly adjusted as table. That will result in something like that:
label textfield
textfield
Just re-read the question. Just replace the JLabels with JComboBoxes and it answers your question a little bit better ;)