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JButton and JTextField

What's wrong? ImageIcon and the frame's size are working properly.
But the JTextField and the JButton aren't.
I need the solution.
import javax.swing.*;
import javax.swing.ImageIcon;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class Frame {
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setTitle("Alkalmazás");
frame.setVisible(true);
frame.setSize(500,500);
frame.setResizable(false);
JTextField field = new JTextField();
field.setBounds(40,250, 300,35);
JButton button = new JButton(new ImageIcon("table.png"));
button.setBounds(40,400, 250,25);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
tf.setText(""something);
}
});
frame.add(field);
frame.add(button);
}
}

You didn't mention what's "not working properly", but there are a few errors with your code:
Don't call your class Frame, it may confuse you or others about java.awt.Frame, something that may work would be MyFrame
Right now all your class is inside the main method and it's not placed inside the Event Dispatch Thread (EDT), to fix this, create an instance of your class and call a method createAndShowGUI (or whatever you want to name it) inside SwingUtilities.invokeLater()
For Example:
public static void main(String args[]) {
SwingUtilities.invokeLater(new MyFrame()::createAndShowGUI)
}
Or if using Java 7 or lower, use the code inside this answer in point #2.
setVisible(true) should be the last line in your code, otherwise you may find some visual glitches that may be resolved until you move your mouse above your window or something that triggers the call to repaint() of your components.
Instead of calling setSize(...) directly, you should override getPreferredSize(...) of your JPanel and then call pack() on your JFrame, see this question and the answers in it: Should I avoid the use of set(Preferred|Maximum|Minimum)Size methods in Java Swing?
You're adding 2 components to the CENTER of BorderLayout, which is a JFrame's default layout manager, there are other layout managers and you can combine them to make complex GUI's.
setBounds(...) might mean that you're using null-layout, which might seem like the easiest way to create complex layouts, however you will find yourself in situations like this one if you take that approach, it's better to let Swing do the calculations for you while you use layout managers. For more, read: Why is it frowned upon to use a null layout in Swing?
With all the above tips now in mind, you may have a code similar to this one:
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class MyFrame {
private JFrame frame;
private JPanel pane;
private JTextField field;
private JButton button;
public static void main(String[] args) {
SwingUtilities.invokeLater(new MyFrame()::createAndShowGUI);
}
private void createAndShowGUI() {
frame = new JFrame("Alkalmazás");
pane = new JPanel() {
#Override
public Dimension getPreferredSize() {
return new Dimension(100, 100);
}
};
pane.setLayout(new BoxLayout(pane, BoxLayout.PAGE_AXIS));
field = new JTextField(10);
button = new JButton("Click me");
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
field.setText("something");
}
});
pane.add(field);
pane.add(button);
frame.add(pane);
frame.setResizable(false);
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
Now you have an output similar to this one:
What about you want the JTextField to have a more "normal" size? Like this one:
You'll have to embed field inside another JPanel (with FlowLayout (the default layout manager of JPanel)), and then add that second JPanel to pane, I'm not writing the code for that as I'm leaving that as an exercise to you so you learn how to use multiple layout managers

Attempting to set the layout to BoxLayout

I can't seem to find a solution online for why I'm getting this error on attempted run
I'm working on making a simple test system for a different program when are button press will yield value in a text box. I would like them to be on different lines to make it cleaner, so I looked into layouts. I decided a Box Layout would fit me best. I looked at different examples before attempting this and my code ended up looking like this, (apologies for the messy code)
Update
Got the box layout error to disappear but the code will not center them on the panel/frame. The label and button align left while the textfield becomes very large. I don't need it todo that
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import static javax.swing.BoxLayout.Y_AXIS;
import static javax.swing.SwingConstants.CENTER;
public class button extends JFrame {
static JFrame f;
static JButton b;
static JLabel l;
// main class
public static void main(String[] args)
{
// create a new frame to stor text field and button
f = new JFrame("panel");
BoxLayout layout = new BoxLayout(f, BoxLayout.Y_AXIS);
f.setLayout(layout);
// create a label to display text
l = new JLabel("panel label");
b = new JButton("button1");
JTextField textArea = new JTextField(5);
textArea.setEditable(false);
//textArea.append("Hello World");
// create a panel to add buttons
JPanel p = new JPanel();
// add buttons and textfield to panel
f.add(p);
f.setSize(300, 300);
p.add(l);
p.add(b);
p.setBackground(Color.white);
p.add(textArea);
f.show();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
Random r = new Random();
textArea.setText(String.valueOf(r));
}
});
}
}
Error
Exception in thread "main" java.awt.AWTError: BoxLayout can't be shared
at java.desktop/javax.swing.BoxLayout.checkContainer(BoxLayout.java:461)
at java.desktop/javax.swing.BoxLayout.invalidateLayout(BoxLayout.java:245)
at java.desktop/javax.swing.BoxLayout.addLayoutComponent(BoxLayout.java:278)
at java.desktop/java.awt.Container.addImpl(Container.java:1152)
at java.desktop/java.awt.Container.add(Container.java:1029)
at java.desktop/javax.swing.JFrame.addImpl(JFrame.java:553)
at java.desktop/java.awt.Container.add(Container.java:436)
at button.main(button.java:36)
I would like the three items to all to be stacked one on top of another with a space between them. The order doesn't matter right now.

Swing was first added to the JDK in 1998 and has undergone a lot of changes since. Unfortunately, when you read Web pages about Swing, it is not obvious when that page was last updated. Consequently you may be learning outdated techniques for writing Swing code.
First of all, according to the code you posted, class button does not need to extend class JFrame since you use a static variable as your application's JFrame. Also, JFrame is a top-level container which makes it a special kind of container and not the same kind of continer as a JPanel. You need to set the layout manager for your JPanel and then add the JLabel, JTextField and JButton to that JPanel. And then add the JPanel to the JFrame.
Calling method pack() of class JFrame will automatically set the preferred sizes for the components inside the JFrame. It appears in the code below.
Please also look at Java coding conventions which allows others to more easily read and understand your code. And note that, according to these conventions, I renamed your class from button to Buttons and also because there are already several class in the JDK named Button.
Here is my rewrite of your code...
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.WindowConstants;
public class Buttons implements Runnable {
public void run() {
createAndShowGui();
}
private void createAndShowGui() {
JFrame f = new JFrame("Box");
f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
JPanel p = new JPanel();
BoxLayout layout = new BoxLayout(p, BoxLayout.Y_AXIS);
p.setLayout(layout);
JLabel l = new JLabel("panel label");
JTextField textField = new JTextField(5);
JButton b = new JButton("button1");
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
Random r = new Random();
textField.setText(String.valueOf(r.nextBoolean()));
}
});
p.add(l);
p.add(textField);
p.add(b);
f.add(p);
f.pack();
f.setLocationByPlatform(true);
f.setVisible(true);
}
public static void main(String[] args) {
Buttons instance = new Buttons();
EventQueue.invokeLater(instance);
}
}

setVisible() for cardPanel is not working

I want to make it so the cardPanels are not visible until an action that is not on the cardPanel is completed. For instance, a window opens up when you select a certain Jradiobutton on that window. I want to use setVisible(boolean) to to do this. However, setVisible is not working for some reason. Is there something i'm missing?
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Component;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
public class MainFrame extends JFrame {
private JFrame frame = new JFrame("Swing Refresh Bug?");
private Container contentPane = frame.getContentPane();
private JPanel cardPanel = new JPanel();
private CardLayout cardLayout = new CardLayout();
private Component currentComponent;
private JButton next;
MainFrame() {
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// properties of the cardPanel
cardPanel.setLayout(cardLayout);
cardPanel.add(new JLabel("One"), "One");
cardPanel.add(new JLabel("Two"), "Two");
cardPanel.add(new JLabel("Three"), "Three");
cardPanel.setVisible(false);
// Create a radio button
JRadioButton addNext = new JRadioButton("Add next");
// Add the radio buttons listener
addNext.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
cardLayout.show(cardPanel, "One");
}
});
// Set the layout of the content pane.
contentPane.setLayout(new BorderLayout());
contentPane.add(cardPanel, BorderLayout.CENTER);
contentPane.add(addNext, BorderLayout.SOUTH);
frame.pack();
frame.setVisible(true);
}
public MainFrame(String title) {
MainFrame mf = new MainFrame();
}
}

Your class need not extend JFrame, you have already created JFrame in the class, if you want to move accross the cards then change ActionListener as follows
addNext.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
cardLayout.next(cardPanel);
}
});

You set your cardPanel not visible by setVisible(false) but you never set it to true after, so your cardPanel (containing your cardLayout) is never shown !
If you want your cardLayout to appear when pressing the radiobutton, you just have to add the setVisible(true) in the listener.
You can also use the isSelected() method from JRadioButton to check if it is clicked or not. For example :
addNext.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if(addNext.isSelected()){
cardPanel.setVisible(true);
cardLayout.show(cardPanel, "One");
}
else{
cardPanel.setVisible(false);
//or : cardLayout.show(cardPanel, "Two");
}
}
});
If you want a JFrame to be opened this way, just creat it before, setting it not visible. Then, you set it visible in the listener.
I hope it helped :)

Initialize it in the ActionListener not in the constructor. You must also say setVisible(true) after that. I think you can make CardPannel class which extends JPannel. There is more point of doing it like that. Instead of adding JLabels in the MainFrame constructor do it in the CardPannel constructor. I am on my phone so I can't show you code right now. I hope I helped.

To add Scroller in JFrame which have JPanel Dynamic

I have two files, one is Main.java and the second is frame.java.
I'm creating a desktop application so I want to add scrollpane as needed vertically or horizontally in Main.java file.
Frame.java throws the JPanel object which is being catched by Main.java and dynamically loaded into JFrame.
So anyone please tell me, how can I add the scrollpane or scrollbar. Which is best, I don't know. Thank you..
Main.java:
package pack;
import java.awt.BorderLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Main {
public static void main(String[] args) {
JPanel pn = null;
JFrame mainFrame = null;
frame login = new frame();
mainFrame = new JFrame("Prem");
mainFrame.setLayout(new BorderLayout());
mainFrame.setDefaultCloseOperation(mainFrame.EXIT_ON_CLOSE);
mainFrame.setSize(500,500);
mainFrame.setLocationRelativeTo(null);
pn=login.getLogin();
mainFrame.add(pn,BorderLayout.CENTER);
mainFrame.setVisible(true);
}
public Main() {
super();
}
}
This is second file which throws the panel object from method frame.java
package pack;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.AbstractAction;
import java.awt.*;
import java.awt.event.*;
public class frame {
JPanel pane = null,pane1=null;
JTextField userText=null,passText=null;
JLabel userLabel =null,passLabel=null,errorLabel=null;
JButton submitLogin = null;
public frame()
{
pane = new JPanel();
pane.setLayout(null);
}
public JPanel getLogin()
{
userLabel = new JLabel("UserName");
pane.add(userLabel);
userLabel.setBounds(5,10,100, 30);
userText = new JTextField();
pane.add(userText);
userText.setBounds(110,10,120,30);
passLabel = new JLabel("PassWord");
pane.add(passLabel);
passLabel.setBounds(5,60,100, 30);
passText = new JTextField();
pane.add(passText);
passText.setBounds(110,60,120,30);
errorLabel = new JLabel("");
pane.add(errorLabel);
errorLabel.setBounds(5,150,180,30);
submitLogin = new JButton("Submit");
pane.add(submitLogin);
submitLogin.setBounds(80,110,90,30);
submitLogin.addActionListener(new AbstractAction(){
public void actionPerformed(ActionEvent e)
{
if(submitLogin.getActionCommand() == "Submit")
{
if(userText.getText().isEmpty() || passText.getText().isEmpty())
{
errorLabel.setText("Enter UserName And Password");
}
else
{
//connection
}
}
else
{
System.exit(0);
}
}
});
return pane;
}
}

You have several issues with that code including:
You don't show us in your code where you're trying to use a JScrollPane or even where it's needed. If you show us your attempt to use this, we'll get a much better understanding of your problem.
You are using a null layout and setBounds(...), something you should avoid at almost all costs, and something which absolutely must be avoided if you want to use a JScrollPane, since JScrollPane's do not work well with null layouts. Instead read up on and use layout managers.
You're comparing Strings using the == operator. You don't want to compare Strings using ==. Use the equals(...) or the equalsIgnoreCase(...) method instead. Understand that == checks if the two objects are the same which is not what you're interested in. The methods on the other hand check if the two Strings have the same characters in the same order, and that's what matters here.
You can find links to the Swing tutorials and other Swing resources here: Swing Info
You can find the layout manager tutorial here: Layout Manager Tutorial.
You can learn about "nesting" layouts here.
You can find specific information on how to use JScrollPanes here: JScrollPane Tutorial.
The basic use of them is that you will want to add your scrollable component to the JScrollPane's viewport, and then add the JScrollPane to the GUI. The specifics of how to do this will all depend on your needs, something we don't yet know, but again is very well explained in the tutorials that I've linked to above.

JTextField is blanking out my JPanels

I am attempting to learn more about creating more dynamic GUI's. I am hoping to add different panels with different content and as you press buttons on one main panel, it changes the adjacent panels. I have added two panels and some buttons and when I test the program, it displays correctly. The problem is when I add a JTextField (or JTextArea) the panels are blank and there are no buttons. The strange thing is I haven't added the JTextField to either panel. I have only created a global variable. If I comment it out, the program runs correctly. Am I missing something very simple?
Here is the gameWindow class that has the JTextField
package rpgcreator;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;
class gameWindow extends JPanel {
JPanel startWindowPanel;
JPanel settingsPanel;
JPanel characterPanel;
JPanel scenarioPanel;
JPanel mapPanel;
JButton CharacterButton = new JButton("Create your character");
JButton StoryButton = new JButton("Choose your Story line");
JButton MapButton = new JButton("Choose your World");
//JTextField nameField = new JTextField(15); //comment or uncomment to see issue
public gameWindow() {
setLayout(new GridLayout(0,2,5,0));
startWindowPanel = new JPanel(new FlowLayout());
settingsPanel = new JPanel(new GridLayout(2,1));
startWindowPanel.setBackground(Color.blue);
settingsPanel.setBackground(Color.black);
startWindowPanel.add(MapButton);
startWindowPanel.add(StoryButton);
startWindowPanel.add(CharacterButton);
add(startWindowPanel);
add(settingsPanel);
}
}
Here is main
package rpgcreator;
import javax.swing.JFrame;
public class RPGCreator extends JFrame{
private static void mainWindow(){
RPGCreator mainwindow = new RPGCreator();
mainwindow.setSize(1200, 800);
mainwindow.setResizable(false);
mainwindow.setLocationRelativeTo(null);
mainwindow.setTitle("RPG Creator");
mainwindow.setVisible(true);
mainwindow.add(new gameWindow());
mainwindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
// TODO code application logic here
mainWindow();
}
}

setVisible should go at the end. You're currently setting visible to true, and then adding a panel.
mainwindow.setVisible(true);
mainwindow.add(new gameWindow());
Put setVisible at the end after setDeaultCLoseOperation

I'm not entirely sure why it does it, maybe someone else can explain.
What I do know, is I usually call pack() which seems to make your problem go away.
private static void mainWindow(){
final RPGCreator mainwindow = new RPGCreator();
mainwindow.setMinimumSize(new Dimension(1200, 800));
mainwindow.setResizable(false);
mainwindow.setTitle("RPG Creator");
mainwindow.setVisible(true);
mainwindow.add(new gameWindow());
mainwindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainwindow.pack(); //This usually goes after you've added all of your components
mainwindow.setLocationRelativeTo(null);
}
Some notes:
I had to change to mainwindow.setMinimumSize(new Dimension(1200, 800)); to avoid the frame looking squashed. Although I would usually let the layout manager deal with the sizes of things.
Call setLocationRelativeTo(null) after you call pack() so that it has the desired effect. Again not sure why, but I've learnt that through some hardship.